Blog作业3
第九次作业
7-1 统计Java程序中关键词的出现次数
作者 段喜龙
单位 南昌航空大学
编写程序统计一个输入的Java源码中关键字（区分大小写）出现的次数。说明如下：
Java中共有53个关键字（自行百度）
从键盘输入一段源码，统计这段源码中出现的关键字的数量
注释中出现的关键字不用统计
字符串中出现的关键字不用统计
统计出的关键字及数量按照关键字升序进行排序输出
未输入源码则认为输入非法
输入格式:
输入Java源码字符串，可以一行或多行，以exit行作为结束标志
输出格式:
当未输入源码时，程序输出Wrong Format
当没有统计数据时，输出为空
当有统计数据时，关键字按照升序排列，每行输出一个关键字及数量，格式为数量\t关键字
输入样例:
在这里给出一组输入。例如：
//Test public method
public HashMap(int initialCapacity) {
this(initialCapacity, DEFAULT_LOAD_FACTOR);
}
public HashMap(int initialCapacity, float loadFactor) {
if (initialCapacity < 0)
throw new IllegalArgumentException("Illegal initial capacity: " +
initialCapacity);
if (initialCapacity > MAXIMUM_CAPACITY)
initialCapacity = MAXIMUM_CAPACITY;
if (loadFactor <= 0 || Float.isNaN(loadFactor))
throw new IllegalArgumentException("Illegal load factor: " +
loadFactor);
this.loadFactor = loadFactor;
this.threshold = tableSizeFor(initialCapacity);
}
exit
输出样例:
在这里给出相应的输出。例如：
1 float
3 if
2 int
2 new
2 public
3 this
2 throw
代码：
import java.util.*;
public class Main {
static Scanner sc = new Scanner(System.in);
static TreeMap<String, Integer> treeMap;
public static void main(String[] args) {
initializeKeywords();
processInput();
printKeywordCounts();
}
static void initializeKeywords() {
StringBuilder stringBuilder = new StringBuilder("abstract、assert、boolean、break、byte、case、catch、char、class、continue、default、do、double、else、enum、extends、final、finally、float、for、if、implements、import、int、interface、instanceof、long、native、new、package、private、protected、public、return、short、static、strictfp、super、switch、synchronized、this、throw、throws、transient、try、void、volatile、while、goto、const、true、false、null");
String[] keywords = stringBuilder.toString().split("\\、");
treeMap = new TreeMap<>();
for (String s : keywords) {
treeMap.put(s, 0);
}
}
static void processInput() {
boolean isEmpty = true;
int index2 = -1, index3 = -1, flag = 0; //注释2标记
int index4 = -1; //引用标记
while (true) {
StringBuilder temp = new StringBuilder(sc.nextLine());
int index1 = temp.indexOf("//");
if (temp.toString().contains("\"")) {
index4 = temp.indexOf("\"") + 1;
if (index4 + 1 < temp.length()) {
while (temp.toString().charAt(index4) != '\"') {
temp.delete(index4, index4 + 1);
if (index4 + 1 >= temp.length())
break;
}
}
if (index4 + 1 < temp.length())
temp.delete(index4, index4 + 1);
}
if (temp.toString().contains("/*"))
index2 = temp.indexOf("/*");
if (temp.toString().contains("*/")) {
index3 = temp.indexOf("*/");
}
if (index2 != 0 && index3 != 0 && !temp.toString().contains("/*")) {
flag = 1;
}
if (index1 != -1) {
temp.replace(index1, temp.length(), "");
}
if (index2 != -1) {
if (index3 != -1) {
temp.replace(index2, index3 + 2, "");
index2 = -1;
index3 = -1;
flag = 0;
} else {
if (flag == 0)
temp.replace(index2, temp.length(), "");
else if (flag == 1)
temp.replace(0, temp.length(), "");
continue;
}
}
String[] strings = temp.toString().split("[^]a-zA-Z=\\-\\*+/\\^]+");
for (String s : strings) {
if (treeMap.containsKey(s)) {
treeMap.replace(s, treeMap.get(s) + 1);
}
}
if (temp.toString().equals("exit")) {
if (isEmpty) {
System.out.println("Wrong Format");
return;
} else
break;
}
isEmpty = false;
}
}
static void printKeywordCounts() {
for (Map.Entry<String, Integer> entry : treeMap.entrySet()) {
Integer integer = entry.getValue();
if (integer != 0) {
System.out.println(integer + "\t" + entry.getKey());
}
}
}
}
import java.util.*;
public class Main {
static Scanner sc = new Scanner(System.in);
static TreeMap<String, Integer> treeMap;
public static void main(String[] args) {
initializeKeywords();
processInput();
printKeywordCounts();
}
static void initializeKeywords() {
StringBuilder stringBuilder = new StringBuilder("abstract、assert、boolean、break、byte、case、catch、char、class、continue、default、do、double、else、enum、extends、final、finally、float、for、if、implements、import、int、interface、instanceof、long、native、new、package、private、protected、public、return、short、static、strictfp、super、switch、synchronized、this、throw、throws、transient、try、void、volatile、while、goto、const、true、false、null");
String[] keywords = stringBuilder.toString().split("\\、");
treeMap = new TreeMap<>();
for (String s : keywords) {
treeMap.put(s, 0);
}
}
static void processInput() {
boolean isEmpty = true;
int index2 = -1, index3 = -1, flag = 0; //注释2标记
int index4 = -1; //引用标记
while (true) {
StringBuilder temp = new StringBuilder(sc.nextLine());
int index1 = temp.indexOf("//");
if (temp.toString().contains("\"")) {
index4 = temp.indexOf("\"") + 1;
if (index4 + 1 < temp.length()) {
while (temp.toString().charAt(index4) != '\"') {
temp.delete(index4, index4 + 1);
if (index4 + 1 >= temp.length())
break;
}
}
if (index4 + 1 < temp.length())
temp.delete(index4, index4 + 1);
}
if (temp.toString().contains("/*"))
index2 = temp.indexOf("/*");
if (temp.toString().contains("*/")) {
index3 = temp.indexOf("*/");
}
if (index2 != 0 && index3 != 0 && !temp.toString().contains("/*")) {
flag = 1;
}
if (index1 != -1) {
temp.replace(index1, temp.length(), "");
}
if (index2 != -1) {
if (index3 != -1) {
temp.replace(index2, index3 + 2, "");
index2 = -1;
index3 = -1;
flag = 0;
} else {
if (flag == 0)
temp.replace(index2, temp.length(), "");
else if (flag == 1)
temp.replace(0, temp.length(), "");
continue;
}
}
String[] strings = temp.toString().split("[^]a-zA-Z=\\-\\*+/\\^]+");
for (String s : strings) {
if (treeMap.containsKey(s)) {
treeMap.replace(s, treeMap.get(s) + 1);
}
}
if (temp.toString().equals("exit")) {
if (isEmpty) {
System.out.println("Wrong Format");
return;
} else
break;
}
isEmpty = false;
}
}
static void printKeywordCounts() {
for (Map.Entry<String, Integer> entry : treeMap.entrySet()) {
Integer integer = entry.getValue();
if (integer != 0) {
System.out.println(integer + "\t" + entry.getKey());
}
}
}
}
7-1 统计Java程序中关键词的出现次数
代码：
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.Map;
import java.util.TreeMap;
public class Main {
public static void main(String[] args) {
Scanner x = new Scanner(System.in);
StringBuilder a = new StringBuilder();
Map map=new TreeMap();
String[] gjc = {"abstract", "assert", "boolean", "break", "byte", "case", "catch", "char", "class", "const", "continue", "default", "do", "double", "else", "enum", "extends", "false", "final", "finally", "float", "for", "goto", "if", "implements", "import", "instanceof", "int", "interface", "long", "native", "new", "null", "package", "private", "protected", "public", "return", "short", "static", "strictfp", "super", "switch", "synchronized", "this", "throw", "throws", "transient", "true", "try", "void", "volatile", "while"};
String kg,exit="exit";
int i,n,flag=0;
kg = x.nextLine();
while( !kg.equals(exit)) {
a.append(kg.replaceAll("//.*", " ").replaceAll("\".*\"", " "));//去掉"//"后和的内容以及双引号里的内容
kg = x.nextLine();
flag=1;
}
String b = a.toString().replaceAll("/\\*\\s*.*\\s*\\*/", " ");//去掉"/* */"里的内容,放入字符串b中
if(flag==0) {
System.out.println("Wrong Format");
}
// 循环找每个关键词出现的次数
for(i=0;i< gjc.length;i++) {
Pattern pattern = Pattern.compile("\\b"+gjc[i]+"\\b");//创建关键词的正则表达式
Matcher matcher = pattern.matcher(b);//字符串与关键词匹配
n=0;
while(matcher.find()) {//找到该关键词的话,记录该关键词的次数
n++;
}
if(n!=0){//把次数不是0的关键词替换为次数
map.put(gjc[i], n);
}
}
String map1= String.valueOf(map);//把map转化为字符串map1
//System.out.println(map1);
String map2=map1.replace("{","").replace("}","");
//System.out.println(map2);
String[] map3=map2.split(", ");
for (i=0;i< map3.length;i++){
String[] map4=map3[i].split("=");
System.out.println(map4[1]+"\t"+map4[0]);
}
}
}
7-1 课程成绩统计程序-1
代码：
import java.util.*;
import java.text.Collator;
import java.util.ArrayList;
import java.util.Locale;
import java.util.Objects;
class Course implements Comparable<Course>{
String name;
int type;//0为必修，1为选修
int mode=0;//0为考试，1为考察
public Course(String name, int type, int mode) {
this.name = name;
this.type = type;
this.mode = mode;
}
public Course(String name,int type){
this.name=name;
this.type=type;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Course course = (Course) o;
return Objects.equals(name, course.name);
}
@Override
public int hashCode() {
return Objects.hash(name);
}
@Override
public int compareTo(Course o) {
return Collator.getInstance(Locale.CHINA).compare(this.name, o.name);
}
}
class CourseSelection {
Course course;
Student student;
Score score;
public CourseSelection(Course course, Student student, Score score) {
this.course = course;
this.student = student;
this.score = score;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
CourseSelection that = (CourseSelection) o;
return Objects.equals(course, that.course) && Objects.equals(student, that.student);
}
@Override
public int hashCode() {
return Objects.hash(course, student);
}
}
class ExamineScore extends Score{
@Override
Integer getScore() {
return this.finalScore;
}
public ExamineScore(){
type=1;
}
}
class ExamScore extends Score{
@Override
Integer getScore() {
return (int)( this.usualScore*0.3+this.finalScore*0.7);
}
public ExamScore(){
type=0;
}
}
abstract class Score {
Integer finalScore=0;
int type;
Integer usualScore=0;
abstract Integer getScore();
}
class Student implements Comparable<Student>{
String id;
String name;
public Student(String id, String name) {
this.id = id;
this.name = name;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Student student = (Student) o;
return Objects.equals(id, student.id);
}
@Override
public int hashCode() {
return Objects.hash(id);
}
@Override
public int compareTo(Student s) {
return this.id.compareTo(s.id);
}
}
public class Main {
public static void main(String[]args){
Scanner scanner=new Scanner(System.in);
HashSet<CourseSelection>courseSelectionHashSet=new HashSet<>();
HashSet<String>courseNameSet=new HashSet<>();
HashMap<Student,Boolean>studentScorehashMap=new HashMap<>();
TreeMap<Student,Integer>averageStudentScore=new TreeMap<>();//综合
TreeMap<Course,Integer>courseUsualAverage=new TreeMap<>();//平时
TreeMap<Course,Integer>courseFinalAverage=new TreeMap<>();//期末
TreeMap<Course,Integer>courseTotalAverage=new TreeMap<>();//结合
TreeMap<String,Integer>classTotalAverage=new TreeMap<>();//班级
while(true){
String temp=scanner.nextLine();
if(temp.equals("end")){
break;
}
String[] s = temp.split(" ");
if(s[0].matches("[0-9]{0,100}")){
if(s.length!=5&&s.length!=4){
System.out.println("wrong format");
continue;
}
Student student=new Student(s[0],s[1]);
Course course=null;
if(s[3].contains(".")){
System.out.println("wrong format");
continue;
}else if(s.length==5&&s[4].contains(".")){
System.out.println("wrong format");
continue;
}
if(s[0].length()!=8||s[1].length()>10||s[2].length()>10||Integer.parseInt(s[3])<0||Integer.parseInt(s[3])>100){
System.out.println("wrong format");
continue;
}else if(s.length==5&&((Integer.parseInt(s[4])<0)||(Integer.parseInt(s[4])>100))){
System.out.println("wrong format");
continue;
}
if(courseNameSet.contains(s[2])){
for(Course tempCourse:courseUsualAverage.keySet()){
if(tempCourse.name.equals(s[2]))
{course=tempCourse;break;}
}
}else {
System.out.println(s[2]+" does not exist");
averageStudentScore.put(student,0);
classTotalAverage.put(s[0].substring(0,6),0);
continue;
}
Score score=new ExamScore();
if(s.length==4&&course.mode==1){
score=new ExamineScore();
score.finalScore=Integer.parseInt(s[3]);
}else if(s.length==5&&course.mode==0){
score=new ExamScore();
score.usualScore=Integer.parseInt(s[3]);score.finalScore=Integer.parseInt(s[4]);
}
classTotalAverage.put(s[0].substring(0,6),0);
if((s.length==4&&course.mode==0)||(s.length==5&&course.mode==1)){
System.out.println(s[0]+" "+s[1]+" "+": access mode mismatch");
averageStudentScore.put(student,0);
continue;
}
//获取每个同学，以便计算平均分
averageStudentScore.put(student,0);
CourseSelection courseSelection=new CourseSelection(course,student,score);
courseSelectionHashSet.add(courseSelection);
}else{
if(s.length!=3&&s.length!=2){
System.out.println("wrong format");
continue;
}
if((s.length==3)&&(s[0].length()>10||(!s[1].equals("必修")&&!s[1].equals("选修"))||(!s[2].equals("考试")&&!s[2].equals("考察")))){
System.out.println("wrong format");
continue;
}else if((s.length==2)&&(s[0].length()>10||!s[1].equals("必修"))){
System.out.println("wrong format");
continue;
}
Course course=new Course(s[0],s[1].equals("必修")?0:1);
if(s.length==3)
course.mode=s[2].equals("考试")?0:1;
if(course.type==0&&course.mode==1){
System.out.println(s[0]+" : course type & access mode mismatch");
continue;
}
courseUsualAverage.put(course,0);
courseFinalAverage.put(course,0);
courseTotalAverage.put(course,0);
courseNameSet.add(s[0]);
}
}
//平均成绩，排序
for (Student student : averageStudentScore.keySet()) {
List<Integer> list = new ArrayList<>();
for (CourseSelection courseSelection : courseSelectionHashSet) {
if (courseSelection.student.id.equals(student.id)) {
list.add(courseSelection.score.getScore());
}
}
for (Integer tempScore : list) {
averageStudentScore.replace(student, averageStudentScore.get(student) + tempScore);
}
if(list.size()!=0)
averageStudentScore.replace(student, averageStudentScore.get(student) / list.size());
if (list.size() == 0) {
studentScorehashMap.put(student,false);
System.out.println(student.id + " " + student.name + " " + "did not take any exams");
}else {
studentScorehashMap.put(student,true);
System.out.println(student.id + " " + student.name + " " + averageStudentScore.get(student));
}
}
//计算每门课程的平均 平时分，期末分，综合分
for(Course course:courseUsualAverage.keySet()){
List<Integer>list=new ArrayList<>();
List<Integer>list1=new ArrayList<>();
List<Integer>list2=new ArrayList<>();
//平时分
for(CourseSelection courseSelection:courseSelectionHashSet){
if(courseSelection.course.name.equals(course.name)){
list.add(courseSelection.score.usualScore);
}
}
//期末
for(CourseSelection courseSelection:courseSelectionHashSet){
if(courseSelection.course.name.equals(course.name)){
list1.add(courseSelection.score.finalScore);
}
}
//综合
for(CourseSelection courseSelection:courseSelectionHashSet){
if(courseSelection.course.name.equals(course.name)){
list2.add(courseSelection.score.getScore());
}
}
for(Integer tempScore:list){
courseUsualAverage.replace(course,courseUsualAverage.get(course)+tempScore);
}
for(Integer tempScore:list1){
courseFinalAverage.replace(course,courseFinalAverage.get(course)+tempScore);
}
for(Integer tempScore:list2){
courseTotalAverage.replace(course,courseTotalAverage.get(course)+tempScore);
}
if(list.size()!=0)
courseUsualAverage.replace(course,courseUsualAverage.get(course)/list.size());
if(list1.size()!=0)
courseFinalAverage.replace(course,courseFinalAverage.get(course)/list1.size());
if(list2.size()!=0)
courseTotalAverage.replace(course,courseTotalAverage.get(course)/list2.size());
if(list.size()==0){
System.out.println(course.name+" has no grades yet");
}else{
if(course.mode==0)
System.out.println(course.name+" "+courseUsualAverage.get(course)+" "+courseFinalAverage.get(course)+" "+courseTotalAverage.get(course));
else
System.out.println(course.name+" "+courseFinalAverage.get(course)+" "+courseTotalAverage.get(course));
}
}
//3.计算班级的分数
for(String classId:classTotalAverage.keySet()){
int sum=0;//人数
boolean flag=false;//班级是否有分数记录
for(Student student:averageStudentScore.keySet()){
if(student.id.substring(0,6).equals(classId)){
classTotalAverage.replace(classId,classTotalAverage.get(classId)+averageStudentScore.get(student));
if(studentScorehashMap.get(student)){
flag=true;
sum++;
}
}
}
if(sum!=0)
classTotalAverage.replace(classId,classTotalAverage.get(classId)/sum);
if(flag){
System.out.println(classId+" "+classTotalAverage.get(classId));
}else{
System.out.println(classId+" "+"has no grades yet");
}
}
}
}
类图：
部分代码缺乏注释，不够详细说明代码的作用和实现逻辑，给阅读代码的人理解带来一定困扰。部分变量命名不够语义化，不利于代码的理解和维护，
但代码结构清晰，使用了类和对象来表示学生、课程、选课和成绩等概念，提高了代码的可读性和可维护性。使用了合适的数据结构来存储数据，如HashSet、HashMap和TreeMap等，便于快速查找和操作数据。
7-3 课程成绩统计程序-2
代码：
代码：
import java.util.*;
import java.text.Collator;
import java.util.ArrayList;
import java.util.Locale;
import java.util.Objects;
class Course implements Comparable<Course>{
protected String name;
protected int type;//0为必修，1为选修,2为实验
protected int mode=0;//0为考试，1为考察,2为实验
public Course(String name, int type, int mode) {
this.name = name;
this.type = type;
this.mode = mode;
}
public Course(String name){
this.name=name ;
};
public Course(String name,int type){
this.name=name;
this.type=type;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Course course = (Course) o;
return Objects.equals(name, course.name);
}
@Override
public int hashCode() {
return Objects.hash(name);
}
@Override
public int compareTo(Course o) {
return Collator.getInstance(Locale.CHINA).compare(this.name, o.name);
}
}
class CourseSelection {
protected Course course;
protected Student student;
protected Grade grade;
public CourseSelection(Course course, Student student, Grade grade) {
this.course = course;
this.student = student;
this.grade = grade;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
CourseSelection that = (CourseSelection) o;
return Objects.equals(course, that.course) && Objects.equals(student, that.student);
}
@Override
public int hashCode() {
return Objects.hash(course, student);
}
}
class ExamineGrade extends Grade{
@Override
Integer getGrade() {
return this.finalGrade;
}
public ExamineGrade(){
type=1;
}
}
class ExamScore extends Grade{
@Override
Integer getGrade() {
return (int)( this.usualGrade*0.3+this.finalGrade*0.7);
}
public ExamScore(){
type=0;
}
}
class ExperimentalScore extends Grade{
Integer getGrade(){
Integer result=0;
for(Integer integer:experimentalGrades){
result+=integer;
}
return result/experimentalGrades.size();
}
}
abstract class Grade {
protected Integer finalGrade=0;
protected int type;
protected Integer usualGrade=0;
protected ArrayList<Integer>experimentalGrades=new ArrayList<>();
abstract Integer getGrade();
}
class Student implements Comparable<Student>{
protected String id;
protected String name;
public Student() {
}
public Student(String id, String name) {
this.id = id;
this.name = name;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Student student = (Student) o;
return Objects.equals(id, student.id);
}
@Override
public int hashCode() {
return Objects.hash(id);
}
@Override
public int compareTo(Student s) {
return this.id.compareTo(s.id);
}
}
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
HashSet<CourseSelection> courseSelectionHashSet = new HashSet<>();
HashSet<String> courseNameSet = new HashSet<>();
HashMap<Student, Boolean> studentScorehashMap = new HashMap<>();
TreeMap<Student,Integer>averageStudentScore=new TreeMap<>();//综合
TreeMap<Course,Integer>courseUsualAverage=new TreeMap<>();//平时
TreeMap<Course,Integer>courseFinalAverage=new TreeMap<>();//期末
TreeMap<Course,Integer>courseTotalAverage=new TreeMap<>();//结合
TreeMap<String,Integer>classTotalAverage=new TreeMap<>();//班级
while (true) {
String temp = scanner.nextLine();
if (temp.equals("end")) {
break;
}
String[] s = temp.split(" ");
if (s[0].matches("[0-9]{0,100}")) {
Student student = new Student(s[0], s[1]);
Course course = null;
if(s.length>=5) {
int flag = 0;
for (int i = 4; i < s.length; i++) {
if (!s[i].matches("[0-9]{1,3}")) {
System.out.println("wrong format");
flag = 1;
break;
} else if (Integer.parseInt(s[i]) < 0 || Integer.parseInt(s[i]) > 100) {
System.out.println("wrong format");
flag = 1;
break;
}
}
if (flag == 1)
continue;
}
if (s[0].length() != 8 || s[1].length() > 10 || s[2].length() > 10 || !s[3].matches("[0-9]{1,3}") || (Integer.parseInt(s[3]) < 0 || Integer.parseInt(s[3]) > 100)) {
System.out.println("wrong format");
continue;
}
if (courseNameSet.contains(s[2])) {
for (Course tempCourse : courseUsualAverage.keySet()) {
if (tempCourse.name.equals(s[2])) {
course = tempCourse;
break;
}
}
}
if (s.length == 5 && ((Integer.parseInt(s[4]) < 0) || (Integer.parseInt(s[4]) > 100))) {
System.out.println("wrong format");
continue;
} else if(course!=null&&course.mode==2){
if (!s[3].matches("[4-9]")) {
System.out.println("wrong format");
continue;
}
if (s.length != Integer.parseInt(s[3]) + 4) {
System.out.println(s[0] + " " + s[1] + " " + ": access mode mismatch");
classTotalAverage.put(s[0].substring(0, 6), 0);
averageStudentScore.put(student, 0);
continue;
}
}
if(!courseNameSet.contains(s[2])) {
System.out.println(s[2] + " does not exist");
averageStudentScore.put(student, 0);
classTotalAverage.put(s[0].substring(0, 6), 0);
continue;
}
Grade grade = new ExamScore();
if (s.length == 4 && course.mode == 1) {
grade = new ExamineGrade();
grade.finalGrade = Integer.parseInt(s[3]);
} else if (s.length == 5 && course.mode == 0) {
grade = new ExamScore();
grade.usualGrade = Integer.parseInt(s[3]);
grade.finalGrade = Integer.parseInt(s[4]);
} else if (course.mode == 2) {
grade = new ExperimentalScore();
for (int i = 4; i < s.length; i++) {
grade.experimentalGrades.add(Integer.parseInt(s[i]));
}
}
classTotalAverage.put(s[0].substring(0, 6), 0);
if ((s.length == 4 && course.mode == 0) || (s.length == 5 && course.mode == 1)) {
System.out.println(s[0] + " " + s[1] + " " + ": access mode mismatch");
averageStudentScore.put(student, 0);
continue;
}
//获取每个同学，以便计算平均分
averageStudentScore.put(student, 0);
CourseSelection courseSelection = new CourseSelection(course, student, grade);
courseSelectionHashSet.add(courseSelection);
} else {
if (s.length != 3 && s.length != 2) {
System.out.println("wrong format");
continue;
}
if ((s.length == 3) && (s[0].length() > 10 || ((!s[1].equals("必修") && !s[1].equals("选修") && !s[1].equals("实验")) || (!s[2].equals("考试") && !s[2].equals("考察") && !s[2].equals("实验"))))) {
System.out.println("wrong format");
continue;
} else if ((s.length == 2) && (s[0].length() > 10 || !s[1].equals("必修"))) {
System.out.println("wrong format");
continue;
}
int type = 0;
//选择
if (s[1].equals("必修")) type = 0;
if (s[1].equals("选修")) type = 1;
if (s[1].equals("实验")) type = 2;
Course course = new Course(s[0], type);
if (s.length == 3) {
int mode = 0;
if (s[2].equals("考试")) mode = 0;
if (s[2].equals("考察")) mode = 1;
if (s[2].equals("实验")) mode = 2;
course.mode = mode;
}
if ((course.type == 0 && course.mode == 1) || (course.mode == 2 && course.type != 2) || course.type == 2 && course.mode != 2) {
System.out.println(s[0] + " : course type & access mode mismatch");
continue;
}
courseUsualAverage.put(course, 0);
courseFinalAverage.put(course, 0);
courseTotalAverage.put(course, 0);
courseNameSet.add(s[0]);
}
}
//courseSelectionHashSet.stream().map(s->s.course.name).forEach(System.out::println);
//1.求每个同学平均成绩，排序打印
for (Student student : averageStudentScore.keySet()) {
List<Integer> list = new ArrayList<>();
for (CourseSelection courseSelection : courseSelectionHashSet) {
if (courseSelection.student.id.equals(student.id)) {
list.add(courseSelection.grade.getGrade());
}
}
//List<Integer> list = courseSelectionHashSet.stream().filter(s -> s.student.id.equals(student.id)).map(s -> s.grade.getGrade()).toList();
for (Integer tempScore : list) {
averageStudentScore.replace(student, averageStudentScore.get(student) + tempScore);
}
if (list.size() != 0)
averageStudentScore.replace(student, averageStudentScore.get(student) / list.size());
if (list.size() == 0) {
studentScorehashMap.put(student, false);
System.out.println(student.id + " " + student.name + " " + "did not take any exams");
} else {
studentScorehashMap.put(student, true);
System.out.println(student.id + " " + student.name + " " + averageStudentScore.get(student));
}
}
//每门课程的平均 平时分，期末分，综合分
for (Course course : courseUsualAverage.keySet()) {
List<Integer> list = new ArrayList<>();
List<Integer> list1 = new ArrayList<>();
List<Integer> list2 = new ArrayList<>();
//平时分
for (CourseSelection courseSelection : courseSelectionHashSet) {
if (courseSelection.course.name.equals(course.name)) {
list.add(courseSelection.grade.usualGrade);
}
}
//期末分
for (CourseSelection courseSelection : courseSelectionHashSet) {
if (courseSelection.course.name.equals(course.name)) {
list1.add(courseSelection.grade.finalGrade);
}
}
//综合分
for (CourseSelection courseSelection : courseSelectionHashSet) {
if (courseSelection.course.name.equals(course.name)) {
list2.add(courseSelection.grade.getGrade());
}
}
for (Integer tempScore : list) {
courseUsualAverage.replace(course, courseUsualAverage.get(course) + tempScore);
}
for (Integer tempScore : list1) {
courseFinalAverage.replace(course, courseFinalAverage.get(course) + tempScore);
}
for (Integer tempScore : list2) {
courseTotalAverage.replace(course, courseTotalAverage.get(course) + tempScore);
}
if (list.size() != 0)
courseUsualAverage.replace(course, courseUsualAverage.get(course) / list.size());
if (list1.size() != 0)
courseFinalAverage.replace(course, courseFinalAverage.get(course) / list1.size());
if (list2.size() != 0)
courseTotalAverage.replace(course, courseTotalAverage.get(course) / list2.size());
if (list.size() == 0) {
System.out.println(course.name + " has no grades yet");
} else {
if (course.mode == 0)
System.out.println(course.name + " " + courseUsualAverage.get(course) + " " + courseFinalAverage.get(course) + " " + courseTotalAverage.get(course));
else if(course.mode!=2)
System.out.println(course.name + " " + courseFinalAverage.get(course) + " " + courseTotalAverage.get(course));
else
System.out.println(course.name +" "+ courseTotalAverage.get(course));
}
}
//计算班级的分数
for (String classId : classTotalAverage.keySet()) {
int sum = 0;//人数
boolean flag = false;//班级是否有分数记录
for (Student student : averageStudentScore.keySet()) {
if (student.id.substring(0, 6).equals(classId)) {
classTotalAverage.replace(classId, classTotalAverage.get(classId) + averageStudentScore.get(student));
if (studentScorehashMap.get(student)) {
flag = true;
sum++;
}
}
}
if (sum != 0)
classTotalAverage.replace(classId, classTotalAverage.get(classId) / sum);
if (flag) {
System.out.println(classId + " " + classTotalAverage.get(classId));
} else {
System.out.println(classId + " " + "has no grades yet");
}
}
}
}
类图：
代码注释比较清晰，对于关键部分的功能和逻辑有所说明；实现了对学生和课程的基本操作，包括添加学生、添加课程、录入成绩等，并能计算和打印学生、课程和班级的平均分数。但缺少异常处理机制，没有对输入和运行过程中的异常情况进行处理和恢复
7-2 课程成绩统计程序-3
代码：
代码：
import java.util.*;
import java.text.Collator;
import java.util.ArrayList;
import java.util.Locale;
import java.util.Objects;
class Course implements Comparable<Course>{
String name;
int type;//0为必修，1为选修,2为实验
int mode=0;//0为考试，1为考察,2为实验
public Course(String name, int type, int mode) {
this.name = name;
this.type = type;
this.mode = mode;
}
public Course(String name){
this.name=name ;
};
public Course(String name,int type){
this.name=name;
this.type=type;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Course course = (Course) o;
return Objects.equals(name, course.name);
}
@Override
public int hashCode() {
return Objects.hash(name);
}
@Override
public int compareTo(Course o) {
return Collator.getInstance(Locale.CHINA).compare(this.name, o.name);
}
}
class CourseSelection {
Course course;
Student student;
Grade grade;
public CourseSelection(Course course, Student student, Grade grade) {
this.course = course;
this.student = student;
this.grade = grade;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
CourseSelection that = (CourseSelection) o;
return Objects.equals(course, that.course) && Objects.equals(student, that.student);
}
@Override
public int hashCode() {
return Objects.hash(course, student);
}
}
class ExamineGrade extends Grade{
@Override
Integer getGrade() {
return this.finalGrade;
}
public ExamineGrade(){
type=1;
}
}
class ExamScore extends Grade{
@Override
Integer getGrade() {
if(weight.size()!=0)
return (int)( this.usualGrade* weight.get(0)+this.finalGrade*weight.get(1));
return (int)( this.usualGrade* 0.3+this.finalGrade*0.7);
}
public ExamScore(){
type=0;
}
}
class ExperimentalScore extends Grade{
Integer getGrade(){
float result=0;
for(int i=0;i<experimentalGrades.size();i++){
result+=experimentalGrades.get(i)* weight.get(i);
}
return (int)result;
}
}
abstract class Grade {
Integer finalGrade=0;
int type;
Integer usualGrade=0;
ArrayList<Integer>experimentalGrades=new ArrayList<>();
ArrayList<Float>weight=new ArrayList<>();
abstract Integer getGrade();
}
class Student implements Comparable<Student>{
String id;
String name;
public Student() {
}
public Student(String id, String name) {
this.id = id;
this.name = name;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Student student = (Student) o;
return Objects.equals(id, student.id);
}
@Override
public int hashCode() {
return Objects.hash(id);
}
@Override
public int compareTo(Student s) {
return this.id.compareTo(s.id);
}
}
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
HashSet<CourseSelection> courseSelectionHashSet = new HashSet<>();
HashSet<String> courseNameSet = new HashSet<>();
HashMap<Student, Boolean> studentScorehashMap = new HashMap<>();
TreeMap<Student, Integer> averageStudentScore = new TreeMap<>();
TreeMap<Course, Integer> courseUsualAverage = new TreeMap<>();
TreeMap<Course, Integer> courseFinalAverage = new TreeMap<>();
TreeMap<Course, Integer> courseTotalAverage = new TreeMap<>();
TreeMap<String, Integer> classTotalAverage = new TreeMap<>();
TreeMap<Course, ArrayList<Float>> scoreWeight = new TreeMap<>();
while (true) {
String temp = scanner.nextLine();
if (temp.equals("end")) {
break;
}
String[] s = temp.split(" ");
if (s[0].matches("[0-9]{0,100}")) {
Student student = new Student(s[0], s[1]);
Course course = null;
Grade grade = new ExamScore();
ArrayList<Float>weight=new ArrayList<>();
if (s.length >= 5) {
int flag = 0;
for (int i = 4; i < s.length; i++) {
if (!s[i].matches("[0-9]{1,3}")) {
System.out.println("wrong format");
flag = 1;
break;
} else if (Integer.parseInt(s[i]) < 0 || Integer.parseInt(s[i]) > 100) {
System.out.println("wrong format");
flag = 1;
break;
}
}
if (flag == 1)
continue;
}
if (s[0].length() != 8 || s[1].length() > 10 || s[2].length() > 10 || !s[3].matches("[0-9]{1,3}") || (Integer.parseInt(s[3]) < 0 || Integer.parseInt(s[3]) > 100)) {
System.out.println("wrong format");
continue;
}
if (courseNameSet.contains(s[2])) {
for (Course tempCourse : courseUsualAverage.keySet()) {
if (tempCourse.name.equals(s[2])) {
grade.weight = scoreWeight.get(tempCourse);
weight=grade.weight;
course = tempCourse;
break;
}
}
}
if (s.length == 5 && ((Integer.parseInt(s[4]) < 0) || (Integer.parseInt(s[4]) > 100))) {
System.out.println("wrong format");
continue;
} else if (course != null && course.mode == 2) {
if (s.length != grade.weight.size() + 3) {
System.out.println(s[0] + " " + s[1] + " " + ": access mode mismatch");
classTotalAverage.put(s[0].substring(0, 6), 0);
averageStudentScore.put(student, 0);
continue;
}
}
if (!courseNameSet.contains(s[2])) {
System.out.println(s[2] + " does not exist");
averageStudentScore.put(student, 0);
classTotalAverage.put(s[0].substring(0, 6), 0);
continue;
}
if (s.length == 4 && Objects.requireNonNull(course).mode == 1) {
grade = new ExamineGrade();
grade.weight=weight;
grade.finalGrade = Integer.parseInt(s[3]);
} else if (s.length == 5 && Objects.requireNonNull(course).mode == 0) {
grade = new ExamScore();
grade.weight=weight;
grade.usualGrade = Integer.parseInt(s[3]);
grade.finalGrade = Integer.parseInt(s[4]);
} else {
assert course != null;
if (course.mode == 2) {
grade = new ExperimentalScore();
grade.weight=weight;
for (int i = 3; i < s.length; i++) {
grade.experimentalGrades.add(Integer.parseInt(s[i]));
}
}
}
classTotalAverage.put(s[0].substring(0, 6), 0);
if ((s.length == 4 && course.mode == 0) || (s.length == 5 && course.mode == 1)) {
System.out.println(s[0] + " " + s[1] + " " + ": access mode mismatch");
averageStudentScore.put(student, 0);
continue;
}
averageStudentScore.put(student, 0);
CourseSelection courseSelection = new CourseSelection(course, student, grade);
courseSelectionHashSet.add(courseSelection);
} else {
if (!s[1].equals("实验") && s.length != 3 && s.length != 2&&s.length!=5) {
System.out.println("wrong format");
continue;
}
if(s[2].equals("考察")&&s.length>=5){
System.out.println("wrong format");
continue;
}
if ((s.length == 3) && (s[0].length() > 10 || ((!s[1].equals("必修") && !s[1].equals("选修") && !s[1].equals("实验")) || (!s[2].equals("考试") && !s[2].equals("考察") && !s[2].equals("实验"))))) {
System.out.println("wrong format");
continue;
}
int type = 0;
ArrayList<Float> arrayList = new ArrayList<>();
if (s[1].equals("必修")) type = 0;
if (s[1].equals("选修")) type = 1;
if (s[1].equals("实验")) type = 2;
Course course = new Course(s[0], type);
int mode = 0;
if (s[2].equals("考试")) mode = 0;
if (s[2].equals("考察")) mode = 1;
if (s[2].equals("实验")) mode = 2;
course.mode = mode;
if ((course.type == 0 && course.mode == 1) || (course.mode == 2 && course.type != 2) || course.type == 2 && course.mode != 2) {
System.out.println(s[0] + " : course type & access mode mismatch");
continue;
}
if (s[1].equals("实验") && !s[3].matches("[4-9]")) {
System.out.println("wrong format");
continue;
} else if (s[1].equals("实验") && Integer.parseInt(s[3]) + 4 != s.length) {
System.out.println(course.name + " : number of scores does not match");
continue;
} else if ((s[1].equals("必修") && (int)(Float.parseFloat(s[3]) + Float.parseFloat(s[4])) != 1)) {
System.out.println(course.name + " : weight value error");
continue;
} else if (s[1].equals("实验")) {
int n = Integer.parseInt(s[3]);
float sum = 0;
for (int i = 0; i < n; i++) {
float tempFloat = Float.parseFloat(s[i + 4]);
sum += tempFloat;
arrayList.add(tempFloat);
}
if (sum != 1) {
System.out.println(course.name + " : weight value error");
continue;
}
} else if (s[2].equals("考试")) {
arrayList.add(Float.parseFloat(s[3]));
arrayList.add(Float.parseFloat(s[4]));
}
if(courseNameSet.contains(course.name)){
continue;
}
scoreWeight.put(course, arrayList);
courseUsualAverage.put(course, 0);
courseFinalAverage.put(course, 0);
courseTotalAverage.put(course, 0);
courseNameSet.add(s[0]);
}
}
for (Student student : averageStudentScore.keySet()) {
List<Integer> list = new ArrayList<>();
for (CourseSelection courseSelection : courseSelectionHashSet) {
if (courseSelection.student.id.equals(student.id)) {
list.add(courseSelection.grade.getGrade());
}
}
for (Integer tempScore : list) {
averageStudentScore.replace(student, averageStudentScore.get(student) + tempScore);
}
if (list.size() != 0)
averageStudentScore.replace(student, averageStudentScore.get(student) / list.size());
if (list.size() == 0) {
studentScorehashMap.put(student, false);
System.out.println(student.id + " " + student.name + " " + "did not take any exams");
} else {
studentScorehashMap.put(student, true);
System.out.println(student.id + " " + student.name + " " + averageStudentScore.get(student));
}
}
for (Course course : courseUsualAverage.keySet()) {
List<Integer> list = new ArrayList<>();
List<Integer> list1 = new ArrayList<>();
List<Integer> list2 = new ArrayList<>();
//平时分
for (CourseSelection courseSelection : courseSelectionHashSet) {
if (courseSelection.course.name.equals(course.name)) {
list.add(courseSelection.grade.usualGrade);
}
}
//期末分
for (CourseSelection courseSelection : courseSelectionHashSet) {
if (courseSelection.course.name.equals(course.name)) {
list1.add(courseSelection.grade.finalGrade);
}
}
//综合分
for (CourseSelection courseSelection : courseSelectionHashSet) {
if (courseSelection.course.name.equals(course.name)) {
list2.add(courseSelection.grade.getGrade());
}
}
for (Integer tempScore : list) {
courseUsualAverage.replace(course, courseUsualAverage.get(course) + tempScore);
}
for (Integer tempScore : list1) {
courseFinalAverage.replace(course, courseFinalAverage.get(course) + tempScore);
}
for (Integer tempScore : list2) {
courseTotalAverage.replace(course, courseTotalAverage.get(course) + tempScore);
}
if (list.size() != 0)
courseUsualAverage.replace(course, courseUsualAverage.get(course) / list.size());
if (list1.size() != 0)
courseFinalAverage.replace(course, courseFinalAverage.get(course) / list1.size());
if (list2.size() != 0)
courseTotalAverage.replace(course, courseTotalAverage.get(course) / list2.size());
if (list.size() == 0) {
System.out.println(course.name + " has no grades yet");
} else {
System.out.println(course.name + " " + courseTotalAverage.get(course));
}
}
for (String classId : classTotalAverage.keySet()) {
int sum = 0;
boolean flag = false;
for (Student student : averageStudentScore.keySet()) {
if (student.id.substring(0, 6).equals(classId)) {
classTotalAverage.replace(classId, classTotalAverage.get(classId) + averageStudentScore.get(student));
if (studentScorehashMap.get(student)) {
flag = true;
sum++;
}
}
}
if (sum != 0)
classTotalAverage.replace(classId, classTotalAverage.get(classId) / sum);
if (flag) {
System.out.println(classId + " " + classTotalAverage.get(classId));
} else {
System.out.println(classId + " " + "has no grades yet");
}
}
}
}
类图：
变量命名不规范：代码中存在一些缩写、单个字母的变量命名，降低了代码的可读性和可维护性；缺乏注释：代码中没有足够的注释来解释每个类、方法或关键代码段的功能和用途，增加了阅读和理解代码的难度
踩坑心得：
-
搞清楚运算的方法和算法
- 类与类之间的关系以调用逻辑
改进建议+总结
-
根据需求快速了解并设计出相应类图和方法，以及类与类之间的关系。
- 对于算法和题目中的计算要加强理解
- 了解Java的基本语法，包括变量、数据类型、运算符、表达式、控制流语句等。
- 学习如何使用类、对象和方法，掌握面向对象编程的概念和原则。
- 熟悉数组的使用和常见操作，了解字符串的处理和常用方法。
- 学习异常处理机制，了解如何处理和抛出异常
- 掌握Java的核心类库，如集合框架（List、Set、Map等）和常用类（String、Math等）的使用。
- 学习输入输出操作，包括文件读写和控制台输入输出。
- 理解Java的日期和时间处理，使用Date、Calendar和新的时间API（java.time包）进行日期时间操作。
- 学习多线程编程，了解线程的创建、同步和通信机制
- 深入理解面向对象编程的概念，包括封装、继承、多态等。
- 学习如何设计和实现类、接口和抽象类，理解继承和实现的关系。
- 熟悉设计模式的常用模式，如单例模式、工厂模式、观察者模式等。
- 掌握异常处理的概念和使用，使用try-catch语句捕获和处理异常。
- 学习调试技巧，如使用断点进行代码调试，利用调试工具定位和解决问题。
- 学习使用Java的输入输出流，实现对文件和网络的读写操作。
- 熟悉文件和目录的处理，包括创建、复制、删除和遍历等操作。
- 了解Java开发环境的搭建和配置，如安装JDK、设置环境变量等。
- 学习使用常见的集成开发环境（IDE），如Eclipse、IntelliJ IDEA等，提高开发效率。
- 遵循Java编码规范，如命名规范、代码风格等，提高代码的可读性和可维护性。
- 学习使用构建工具（如Maven或Gradle）管理项目依赖和构建过程。
- 熟悉版本控制工具（如Git），实现代码版本管理和团队协作。
OOP 7~12次作业心得体会
OOP 7~12次作业心得体会
22201709-刘隽涛
目录
（1）对于oop7~12次作业的理解
（2）设计与分析，测试分析性能，踩坑心得及下次改进的建议
（3）总结与看法：）
关于这几次作业的看法：
这7~12次题目集较第一次作业难度有进一步提高，考察抽象类、接口等。主要是围绕课程成绩统计程序进行的。第七次大作业就是成绩统计程序，第8次大作业则增加了对HashMap和多态的一个考察，第十次大作业则是增加了对Array.*部分知识点的考察。第三次写Blog，相比较上一次而言自己的经验更加的丰富了，这次blog的书写相对来说要更为轻松些。内容上题目较少，只需要分析有关课程成绩统计系统，但是说容易也并不容易，每一道题都是刺头中的刺头，这一次写博客，不仅仅是以完成任务的目的，更多的，让自己重新对那些打击过自己，折磨过自己的题目进行一次整体性的回顾。对于这次博客，我把它当作对自己过去几星期在JAVA里旅途的回望，对我付出无数心血的pta大作业的再一次审视，对我这段时间学习的一次总结。
对于OOP7~12次作业难点的理解和出错点分析
第七次作业
1.类的设计，继承与多态，接口
第八次作业
1.类的继承、多态性使用方法以及接口的应用。
第九次作业
1.hashmap和treemap的运用
第十次作业
1.增加了对Array.*部分知识点的考察。
第十一次作业
1.hashmap的检索与排序
第十二次作业
1.自定义接口ArrayIntegerStack
设计与分析
第九次作业
7-1 统计Java程序中关键词的出现次数
作者 段喜龙
单位 南昌航空大学
编写程序统计一个输入的Java源码中关键字（区分大小写）出现的次数。说明如下：
- Java中共有53个关键字（自行百度）
- 从键盘输入一段源码，统计这段源码中出现的关键字的数量
- 注释中出现的关键字不用统计
- 字符串中出现的关键字不用统计
- 统计出的关键字及数量按照关键字升序进行排序输出
- 未输入源码则认为输入非法
输入格式:
输入Java源码字符串，可以一行或多行，以exit行作为结束标志
输出格式:
- 当未输入源码时，程序输出
Wrong Format - 当没有统计数据时，输出为空
- 当有统计数据时，关键字按照升序排列，每行输出一个关键字及数量，格式为
数量\t关键字
输入样例:
在这里给出一组输入。例如：
//Test public method public HashMap(int initialCapacity) { this(initialCapacity, DEFAULT_LOAD_FACTOR); } public HashMap(int initialCapacity, float loadFactor) { if (initialCapacity < 0) throw new IllegalArgumentException("Illegal initial capacity: " + initialCapacity); if (initialCapacity > MAXIMUM_CAPACITY) initialCapacity = MAXIMUM_CAPACITY; if (loadFactor <= 0 || Float.isNaN(loadFactor)) throw new IllegalArgumentException("Illegal load factor: " + loadFactor); this.loadFactor = loadFactor; this.threshold = tableSizeFor(initialCapacity); } exit
输出样例:
在这里给出相应的输出。例如：
1 float 3 if 2 int 2 new 2 public 3 this 2 throw
代码：
import java.util.*; public class Main { static Scanner sc = new Scanner(System.in); static TreeMap<String, Integer> treeMap; public static void main(String[] args) { initializeKeywords(); processInput(); printKeywordCounts(); } static void initializeKeywords() { StringBuilder stringBuilder = new StringBuilder("abstract、assert、boolean、break、byte、case、catch、char、class、continue、default、do、double、else、enum、extends、final、finally、float、for、if、implements、import、int、interface、instanceof、long、native、new、package、private、protected、public、return、short、static、strictfp、super、switch、synchronized、this、throw、throws、transient、try、void、volatile、while、goto、const、true、false、null"); String[] keywords = stringBuilder.toString().split("\\、"); treeMap = new TreeMap<>(); for (String s : keywords) { treeMap.put(s, 0); } } static void processInput() { boolean isEmpty = true; int index2 = -1, index3 = -1, flag = 0; //注释2标记 int index4 = -1; //引用标记 while (true) { StringBuilder temp = new StringBuilder(sc.nextLine()); int index1 = temp.indexOf("//"); if (temp.toString().contains("\"")) { index4 = temp.indexOf("\"") + 1; if (index4 + 1 < temp.length()) { while (temp.toString().charAt(index4) != '\"') { temp.delete(index4, index4 + 1); if (index4 + 1 >= temp.length()) break; } } if (index4 + 1 < temp.length()) temp.delete(index4, index4 + 1); } if (temp.toString().contains("/*")) index2 = temp.indexOf("/*"); if (temp.toString().contains("*/")) { index3 = temp.indexOf("*/"); } if (index2 != 0 && index3 != 0 && !temp.toString().contains("/*")) { flag = 1; } if (index1 != -1) { temp.replace(index1, temp.length(), ""); } if (index2 != -1) { if (index3 != -1) { temp.replace(index2, index3 + 2, ""); index2 = -1; index3 = -1; flag = 0; } else { if (flag == 0) temp.replace(index2, temp.length(), ""); else if (flag == 1) temp.replace(0, temp.length(), ""); continue; } } String[] strings = temp.toString().split("[^]a-zA-Z=\\-\\*+/\\^]+"); for (String s : strings) { if (treeMap.containsKey(s)) { treeMap.replace(s, treeMap.get(s) + 1); } } if (temp.toString().equals("exit")) { if (isEmpty) { System.out.println("Wrong Format"); return; } else break; } isEmpty = false; } } static void printKeywordCounts() { for (Map.Entry<String, Integer> entry : treeMap.entrySet()) { Integer integer = entry.getValue(); if (integer != 0) { System.out.println(integer + "\t" + entry.getKey()); } } } }
圈复杂度：
优点：
- 代码逻辑清晰：代码按照一定的步骤进行初始化、处理输入和输出结果，结构较为清晰，易于理解和维护。
- 使用合适的数据结构：使用了 TreeMap 来存储关键字和对应的出现次数，TreeMap 可以按照关键字的自然顺序进行排序，并且具有较快的查找和插入操作。
- 对输入进行逐行处理：代码逐行读取输入，对每一行进行处理，这样可以有效地控制内存的使用，适用于大型输入。
缺点：
- 命名不规范：变量名使用了单个字母作为标识，不易于理解。建议使用更有意义的变量名来提高代码的可读性。
- 代码可读性较差：代码中存在大量的硬编码，缺乏注释和清晰的逻辑分隔，使得代码可读性较差，不易于理解和维护。
- 部分处理逻辑不完善：对于引用和注释的处理存在一些问题，可能无法正确处理所有情况。例如，引号内的代码和注释内的代码可能会对关键字统计产生干扰。
- 没有错误处理机制：代码没有处理异常情况的机制，例如输入错误格式的代码或者发生 I/O 异常时，没有给出相应的错误提示或处理方式。
第十次作业
7-1 课程成绩统计程序-1
代码：
import java.util.*; import java.text.Collator; import java.util.ArrayList; import java.util.Locale; import java.util.Objects; class Course implements Comparable<Course>{ String name; int type;//0为必修，1为选修 int mode=0;//0为考试，1为考察 public Course(String name, int type, int mode) { this.name = name; this.type = type; this.mode = mode; } public Course(String name,int type){ this.name=name; this.type=type; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Course course = (Course) o; return Objects.equals(name, course.name); } @Override public int hashCode() { return Objects.hash(name); } @Override public int compareTo(Course o) { return Collator.getInstance(Locale.CHINA).compare(this.name, o.name); } } class CourseSelection { Course course; Student student; Score score; public CourseSelection(Course course, Student student, Score score) { this.course = course; this.student = student; this.score = score; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; CourseSelection that = (CourseSelection) o; return Objects.equals(course, that.course) && Objects.equals(student, that.student); } @Override public int hashCode() { return Objects.hash(course, student); } } class ExamineScore extends Score{ @Override Integer getScore() { return this.finalScore; } public ExamineScore(){ type=1; } } class ExamScore extends Score{ @Override Integer getScore() { return (int)( this.usualScore*0.3+this.finalScore*0.7); } public ExamScore(){ type=0; } } abstract class Score { Integer finalScore=0; int type; Integer usualScore=0; abstract Integer getScore(); } class Student implements Comparable<Student>{ String id; String name; public Student(String id, String name) { this.id = id; this.name = name; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Student student = (Student) o; return Objects.equals(id, student.id); } @Override public int hashCode() { return Objects.hash(id); } @Override public int compareTo(Student s) { return this.id.compareTo(s.id); } } public class Main { public static void main(String[]args){ Scanner scanner=new Scanner(System.in); HashSet<CourseSelection>courseSelectionHashSet=new HashSet<>(); HashSet<String>courseNameSet=new HashSet<>(); HashMap<Student,Boolean>studentScorehashMap=new HashMap<>(); TreeMap<Student,Integer>averageStudentScore=new TreeMap<>();//综合 TreeMap<Course,Integer>courseUsualAverage=new TreeMap<>();//平时 TreeMap<Course,Integer>courseFinalAverage=new TreeMap<>();//期末 TreeMap<Course,Integer>courseTotalAverage=new TreeMap<>();//结合 TreeMap<String,Integer>classTotalAverage=new TreeMap<>();//班级 while(true){ String temp=scanner.nextLine(); if(temp.equals("end")){ break; } String[] s = temp.split(" "); if(s[0].matches("[0-9]{0,100}")){ if(s.length!=5&&s.length!=4){ System.out.println("wrong format"); continue; } Student student=new Student(s[0],s[1]); Course course=null; if(s[3].contains(".")){ System.out.println("wrong format"); continue; }else if(s.length==5&&s[4].contains(".")){ System.out.println("wrong format"); continue; } if(s[0].length()!=8||s[1].length()>10||s[2].length()>10||Integer.parseInt(s[3])<0||Integer.parseInt(s[3])>100){ System.out.println("wrong format"); continue; }else if(s.length==5&&((Integer.parseInt(s[4])<0)||(Integer.parseInt(s[4])>100))){ System.out.println("wrong format"); continue; } if(courseNameSet.contains(s[2])){ for(Course tempCourse:courseUsualAverage.keySet()){ if(tempCourse.name.equals(s[2])) {course=tempCourse;break;} } }else { System.out.println(s[2]+" does not exist"); averageStudentScore.put(student,0); classTotalAverage.put(s[0].substring(0,6),0); continue; } Score score=new ExamScore(); if(s.length==4&&course.mode==1){ score=new ExamineScore(); score.finalScore=Integer.parseInt(s[3]); }else if(s.length==5&&course.mode==0){ score=new ExamScore(); score.usualScore=Integer.parseInt(s[3]);score.finalScore=Integer.parseInt(s[4]); } classTotalAverage.put(s[0].substring(0,6),0); if((s.length==4&&course.mode==0)||(s.length==5&&course.mode==1)){ System.out.println(s[0]+" "+s[1]+" "+": access mode mismatch"); averageStudentScore.put(student,0); continue; } //获取每个同学，以便计算平均分 averageStudentScore.put(student,0); CourseSelection courseSelection=new CourseSelection(course,student,score); courseSelectionHashSet.add(courseSelection); }else{ if(s.length!=3&&s.length!=2){ System.out.println("wrong format"); continue; } if((s.length==3)&&(s[0].length()>10||(!s[1].equals("必修")&&!s[1].equals("选修"))||(!s[2].equals("考试")&&!s[2].equals("考察")))){ System.out.println("wrong format"); continue; }else if((s.length==2)&&(s[0].length()>10||!s[1].equals("必修"))){ System.out.println("wrong format"); continue; } Course course=new Course(s[0],s[1].equals("必修")?0:1); if(s.length==3) course.mode=s[2].equals("考试")?0:1; if(course.type==0&&course.mode==1){ System.out.println(s[0]+" : course type & access mode mismatch"); continue; } courseUsualAverage.put(course,0); courseFinalAverage.put(course,0); courseTotalAverage.put(course,0); courseNameSet.add(s[0]); } } //平均成绩，排序 for (Student student : averageStudentScore.keySet()) { List<Integer> list = new ArrayList<>(); for (CourseSelection courseSelection : courseSelectionHashSet) { if (courseSelection.student.id.equals(student.id)) { list.add(courseSelection.score.getScore()); } } for (Integer tempScore : list) { averageStudentScore.replace(student, averageStudentScore.get(student) + tempScore); } if(list.size()!=0) averageStudentScore.replace(student, averageStudentScore.get(student) / list.size()); if (list.size() == 0) { studentScorehashMap.put(student,false); System.out.println(student.id + " " + student.name + " " + "did not take any exams"); }else { studentScorehashMap.put(student,true); System.out.println(student.id + " " + student.name + " " + averageStudentScore.get(student)); } } //计算每门课程的平均 平时分，期末分，综合分 for(Course course:courseUsualAverage.keySet()){ List<Integer>list=new ArrayList<>(); List<Integer>list1=new ArrayList<>(); List<Integer>list2=new ArrayList<>(); //平时分 for(CourseSelection courseSelection:courseSelectionHashSet){ if(courseSelection.course.name.equals(course.name)){ list.add(courseSelection.score.usualScore); } } //期末 for(CourseSelection courseSelection:courseSelectionHashSet){ if(courseSelection.course.name.equals(course.name)){ list1.add(courseSelection.score.finalScore); } } //综合 for(CourseSelection courseSelection:courseSelectionHashSet){ if(courseSelection.course.name.equals(course.name)){ list2.add(courseSelection.score.getScore()); } } for(Integer tempScore:list){ courseUsualAverage.replace(course,courseUsualAverage.get(course)+tempScore); } for(Integer tempScore:list1){ courseFinalAverage.replace(course,courseFinalAverage.get(course)+tempScore); } for(Integer tempScore:list2){ courseTotalAverage.replace(course,courseTotalAverage.get(course)+tempScore); } if(list.size()!=0) courseUsualAverage.replace(course,courseUsualAverage.get(course)/list.size()); if(list1.size()!=0) courseFinalAverage.replace(course,courseFinalAverage.get(course)/list1.size()); if(list2.size()!=0) courseTotalAverage.replace(course,courseTotalAverage.get(course)/list2.size()); if(list.size()==0){ System.out.println(course.name+" has no grades yet"); }else{ if(course.mode==0) System.out.println(course.name+" "+courseUsualAverage.get(course)+" "+courseFinalAverage.get(course)+" "+courseTotalAverage.get(course)); else System.out.println(course.name+" "+courseFinalAverage.get(course)+" "+courseTotalAverage.get(course)); } } //3.计算班级的分数 for(String classId:classTotalAverage.keySet()){ int sum=0;//人数 boolean flag=false;//班级是否有分数记录 for(Student student:averageStudentScore.keySet()){ if(student.id.substring(0,6).equals(classId)){ classTotalAverage.replace(classId,classTotalAverage.get(classId)+averageStudentScore.get(student)); if(studentScorehashMap.get(student)){ flag=true; sum++; } } } if(sum!=0) classTotalAverage.replace(classId,classTotalAverage.get(classId)/sum); if(flag){ System.out.println(classId+" "+classTotalAverage.get(classId)); }else{ System.out.println(classId+" "+"has no grades yet"); } } } }
类图：
圈复杂度：
优点：
- 代码结构清晰，使用了类和对象来表示学生、课程、选课和成绩等概念，提高了代码的可读性和可维护性。
- 使用了合适的数据结构来存储数据，如HashSet、HashMap和TreeMap等，便于快速查找和操作数据。
- 通过重写equals()和hashCode()方法，确保对象在集合中的唯一性。
- 使用了面向对象的设计原则，如封装、继承和多态，提高了代码的可扩展性和重用性。
缺点：
- 部分代码缺乏注释，不够详细说明代码的作用和实现逻辑，给阅读代码的人理解带来一定困扰。
- 部分变量命名不够语义化，不利于代码的理解和维护。
- 部分代码逻辑比较复杂，嵌套层次较深，可读性较差，建议进行适当的重构和简化。
- 部分代码存在冗余和重复，可以考虑提取公共代码块或方法，提高代码的复用性和可维护性。
- 输入数据的格式校验不够严格，可能存在一些输入错误的情况没有进行处理和提示。
第十一次作业
7-3 课程成绩统计程序-2
代码：
import java.util.*; import java.text.Collator; import java.util.ArrayList; import java.util.Locale; import java.util.Objects; class Course implements Comparable<Course>{ protected String name; protected int type;//0为必修，1为选修,2为实验 protected int mode=0;//0为考试，1为考察,2为实验 public Course(String name, int type, int mode) { this.name = name; this.type = type; this.mode = mode; } public Course(String name){ this.name=name ; }; public Course(String name,int type){ this.name=name; this.type=type; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Course course = (Course) o; return Objects.equals(name, course.name); } @Override public int hashCode() { return Objects.hash(name); } @Override public int compareTo(Course o) { return Collator.getInstance(Locale.CHINA).compare(this.name, o.name); } } class CourseSelection { protected Course course; protected Student student; protected Grade grade; public CourseSelection(Course course, Student student, Grade grade) { this.course = course; this.student = student; this.grade = grade; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; CourseSelection that = (CourseSelection) o; return Objects.equals(course, that.course) && Objects.equals(student, that.student); } @Override public int hashCode() { return Objects.hash(course, student); } } class ExamineGrade extends Grade{ @Override Integer getGrade() { return this.finalGrade; } public ExamineGrade(){ type=1; } } class ExamScore extends Grade{ @Override Integer getGrade() { return (int)( this.usualGrade*0.3+this.finalGrade*0.7); } public ExamScore(){ type=0; } } class ExperimentalScore extends Grade{ Integer getGrade(){ Integer result=0; for(Integer integer:experimentalGrades){ result+=integer; } return result/experimentalGrades.size(); } } abstract class Grade { protected Integer finalGrade=0; protected int type; protected Integer usualGrade=0; protected ArrayList<Integer>experimentalGrades=new ArrayList<>(); abstract Integer getGrade(); } class Student implements Comparable<Student>{ protected String id; protected String name; public Student() { } public Student(String id, String name) { this.id = id; this.name = name; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Student student = (Student) o; return Objects.equals(id, student.id); } @Override public int hashCode() { return Objects.hash(id); } @Override public int compareTo(Student s) { return this.id.compareTo(s.id); } } public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); HashSet<CourseSelection> courseSelectionHashSet = new HashSet<>(); HashSet<String> courseNameSet = new HashSet<>(); HashMap<Student, Boolean> studentScorehashMap = new HashMap<>(); TreeMap<Student,Integer>averageStudentScore=new TreeMap<>();//综合 TreeMap<Course,Integer>courseUsualAverage=new TreeMap<>();//平时 TreeMap<Course,Integer>courseFinalAverage=new TreeMap<>();//期末 TreeMap<Course,Integer>courseTotalAverage=new TreeMap<>();//结合 TreeMap<String,Integer>classTotalAverage=new TreeMap<>();//班级 while (true) { String temp = scanner.nextLine(); if (temp.equals("end")) { break; } String[] s = temp.split(" "); if (s[0].matches("[0-9]{0,100}")) { Student student = new Student(s[0], s[1]); Course course = null; if(s.length>=5) { int flag = 0; for (int i = 4; i < s.length; i++) { if (!s[i].matches("[0-9]{1,3}")) { System.out.println("wrong format"); flag = 1; break; } else if (Integer.parseInt(s[i]) < 0 || Integer.parseInt(s[i]) > 100) { System.out.println("wrong format"); flag = 1; break; } } if (flag == 1) continue; } if (s[0].length() != 8 || s[1].length() > 10 || s[2].length() > 10 || !s[3].matches("[0-9]{1,3}") || (Integer.parseInt(s[3]) < 0 || Integer.parseInt(s[3]) > 100)) { System.out.println("wrong format"); continue; } if (courseNameSet.contains(s[2])) { for (Course tempCourse : courseUsualAverage.keySet()) { if (tempCourse.name.equals(s[2])) { course = tempCourse; break; } } } if (s.length == 5 && ((Integer.parseInt(s[4]) < 0) || (Integer.parseInt(s[4]) > 100))) { System.out.println("wrong format"); continue; } else if(course!=null&&course.mode==2){ if (!s[3].matches("[4-9]")) { System.out.println("wrong format"); continue; } if (s.length != Integer.parseInt(s[3]) + 4) { System.out.println(s[0] + " " + s[1] + " " + ": access mode mismatch"); classTotalAverage.put(s[0].substring(0, 6), 0); averageStudentScore.put(student, 0); continue; } } if(!courseNameSet.contains(s[2])) { System.out.println(s[2] + " does not exist"); averageStudentScore.put(student, 0); classTotalAverage.put(s[0].substring(0, 6), 0); continue; } Grade grade = new ExamScore(); if (s.length == 4 && course.mode == 1) { grade = new ExamineGrade(); grade.finalGrade = Integer.parseInt(s[3]); } else if (s.length == 5 && course.mode == 0) { grade = new ExamScore(); grade.usualGrade = Integer.parseInt(s[3]); grade.finalGrade = Integer.parseInt(s[4]); } else if (course.mode == 2) { grade = new ExperimentalScore(); for (int i = 4; i < s.length; i++) { grade.experimentalGrades.add(Integer.parseInt(s[i])); } } classTotalAverage.put(s[0].substring(0, 6), 0); if ((s.length == 4 && course.mode == 0) || (s.length == 5 && course.mode == 1)) { System.out.println(s[0] + " " + s[1] + " " + ": access mode mismatch"); averageStudentScore.put(student, 0); continue; } //获取每个同学，以便计算平均分 averageStudentScore.put(student, 0); CourseSelection courseSelection = new CourseSelection(course, student, grade); courseSelectionHashSet.add(courseSelection); } else { if (s.length != 3 && s.length != 2) { System.out.println("wrong format"); continue; } if ((s.length == 3) && (s[0].length() > 10 || ((!s[1].equals("必修") && !s[1].equals("选修") && !s[1].equals("实验")) || (!s[2].equals("考试") && !s[2].equals("考察") && !s[2].equals("实验"))))) { System.out.println("wrong format"); continue; } else if ((s.length == 2) && (s[0].length() > 10 || !s[1].equals("必修"))) { System.out.println("wrong format"); continue; } int type = 0; //选择 if (s[1].equals("必修")) type = 0; if (s[1].equals("选修")) type = 1; if (s[1].equals("实验")) type = 2; Course course = new Course(s[0], type); if (s.length == 3) { int mode = 0; if (s[2].equals("考试")) mode = 0; if (s[2].equals("考察")) mode = 1; if (s[2].equals("实验")) mode = 2; course.mode = mode; } if ((course.type == 0 && course.mode == 1) || (course.mode == 2 && course.type != 2) || course.type == 2 && course.mode != 2) { System.out.println(s[0] + " : course type & access mode mismatch"); continue; } courseUsualAverage.put(course, 0); courseFinalAverage.put(course, 0); courseTotalAverage.put(course, 0); courseNameSet.add(s[0]); } } //courseSelectionHashSet.stream().map(s->s.course.name).forEach(System.out::println); //1.求每个同学平均成绩，排序打印 for (Student student : averageStudentScore.keySet()) { List<Integer> list = new ArrayList<>(); for (CourseSelection courseSelection : courseSelectionHashSet) { if (courseSelection.student.id.equals(student.id)) { list.add(courseSelection.grade.getGrade()); } } //List<Integer> list = courseSelectionHashSet.stream().filter(s -> s.student.id.equals(student.id)).map(s -> s.grade.getGrade()).toList(); for (Integer tempScore : list) { averageStudentScore.replace(student, averageStudentScore.get(student) + tempScore); } if (list.size() != 0) averageStudentScore.replace(student, averageStudentScore.get(student) / list.size()); if (list.size() == 0) { studentScorehashMap.put(student, false); System.out.println(student.id + " " + student.name + " " + "did not take any exams"); } else { studentScorehashMap.put(student, true); System.out.println(student.id + " " + student.name + " " + averageStudentScore.get(student)); } } //每门课程的平均 平时分，期末分，综合分 for (Course course : courseUsualAverage.keySet()) { List<Integer> list = new ArrayList<>(); List<Integer> list1 = new ArrayList<>(); List<Integer> list2 = new ArrayList<>(); //平时分 for (CourseSelection courseSelection : courseSelectionHashSet) { if (courseSelection.course.name.equals(course.name)) { list.add(courseSelection.grade.usualGrade); } } //期末分 for (CourseSelection courseSelection : courseSelectionHashSet) { if (courseSelection.course.name.equals(course.name)) { list1.add(courseSelection.grade.finalGrade); } } //综合分 for (CourseSelection courseSelection : courseSelectionHashSet) { if (courseSelection.course.name.equals(course.name)) { list2.add(courseSelection.grade.getGrade()); } } for (Integer tempScore : list) { courseUsualAverage.replace(course, courseUsualAverage.get(course) + tempScore); } for (Integer tempScore : list1) { courseFinalAverage.replace(course, courseFinalAverage.get(course) + tempScore); } for (Integer tempScore : list2) { courseTotalAverage.replace(course, courseTotalAverage.get(course) + tempScore); } if (list.size() != 0) courseUsualAverage.replace(course, courseUsualAverage.get(course) / list.size()); if (list1.size() != 0) courseFinalAverage.replace(course, courseFinalAverage.get(course) / list1.size()); if (list2.size() != 0) courseTotalAverage.replace(course, courseTotalAverage.get(course) / list2.size()); if (list.size() == 0) { System.out.println(course.name + " has no grades yet"); } else { if (course.mode == 0) System.out.println(course.name + " " + courseUsualAverage.get(course) + " " + courseFinalAverage.get(course) + " " + courseTotalAverage.get(course)); else if(course.mode!=2) System.out.println(course.name + " " + courseFinalAverage.get(course) + " " + courseTotalAverage.get(course)); else System.out.println(course.name +" "+ courseTotalAverage.get(course)); } } //计算班级的分数 for (String classId : classTotalAverage.keySet()) { int sum = 0;//人数 boolean flag = false;//班级是否有分数记录 for (Student student : averageStudentScore.keySet()) { if (student.id.substring(0, 6).equals(classId)) { classTotalAverage.replace(classId, classTotalAverage.get(classId) + averageStudentScore.get(student)); if (studentScorehashMap.get(student)) { flag = true; sum++; } } } if (sum != 0) classTotalAverage.replace(classId, classTotalAverage.get(classId) / sum); if (flag) { System.out.println(classId + " " + classTotalAverage.get(classId)); } else { System.out.println(classId + " " + "has no grades yet"); } } } }
类图
圈复杂度：
优点：
- 代码使用了面向对象的设计，定义了多个类来表示学生、课程和成绩等概念，使得代码结构清晰，易于理解和维护。
- 使用了合适的数据结构来存储数据，如HashSet、HashMap、TreeMap等，提高了数据的检索效率和存储的准确性。
- 实现了对学生和课程的基本操作，包括添加学生、添加课程、录入成绩等，并能计算和打印学生、课程和班级的平均分数。
- 使用了重写equals和hashCode方法，确保对象比较的准确性。
- 代码注释比较清晰，对于关键部分的功能和逻辑有所说明。
缺点：
- 部分代码命名不够语义化，不符合Java的命名规范，例如Grade类中的experimentalGrades应该命名为experimentalGradeList等。
- 部分方法和逻辑实现较为复杂，可以考虑进行重构，简化代码结构和逻辑。
- 输入数据格式的校验可以进一步优化，提供更详细的错误提示信息，帮助用户更好地理解输入数据的要求。
- 部分方法和变量的访问修饰符没有明确指定，可以进行修正，增强代码的可读性和可维护性。
- 缺少异常处理机制，没有对输入和运行过程中的异常情况进行处理和恢复。
第十二次作业
7-2 课程成绩统计程序-3
代码：
import java.util.*; import java.text.Collator; import java.util.ArrayList; import java.util.Locale; import java.util.Objects; class Course implements Comparable<Course>{ String name; int type;//0为必修，1为选修,2为实验 int mode=0;//0为考试，1为考察,2为实验 public Course(String name, int type, int mode) { this.name = name; this.type = type; this.mode = mode; } public Course(String name){ this.name=name ; }; public Course(String name,int type){ this.name=name; this.type=type; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Course course = (Course) o; return Objects.equals(name, course.name); } @Override public int hashCode() { return Objects.hash(name); } @Override public int compareTo(Course o) { return Collator.getInstance(Locale.CHINA).compare(this.name, o.name); } } class CourseSelection { Course course; Student student; Grade grade; public CourseSelection(Course course, Student student, Grade grade) { this.course = course; this.student = student; this.grade = grade; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; CourseSelection that = (CourseSelection) o; return Objects.equals(course, that.course) && Objects.equals(student, that.student); } @Override public int hashCode() { return Objects.hash(course, student); } } class ExamineGrade extends Grade{ @Override Integer getGrade() { return this.finalGrade; } public ExamineGrade(){ type=1; } } class ExamScore extends Grade{ @Override Integer getGrade() { if(weight.size()!=0) return (int)( this.usualGrade* weight.get(0)+this.finalGrade*weight.get(1)); return (int)( this.usualGrade* 0.3+this.finalGrade*0.7); } public ExamScore(){ type=0; } } class ExperimentalScore extends Grade{ Integer getGrade(){ float result=0; for(int i=0;i<experimentalGrades.size();i++){ result+=experimentalGrades.get(i)* weight.get(i); } return (int)result; } } abstract class Grade { Integer finalGrade=0; int type; Integer usualGrade=0; ArrayList<Integer>experimentalGrades=new ArrayList<>(); ArrayList<Float>weight=new ArrayList<>(); abstract Integer getGrade(); } class Student implements Comparable<Student>{ String id; String name; public Student() { } public Student(String id, String name) { this.id = id; this.name = name; } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; Student student = (Student) o; return Objects.equals(id, student.id); } @Override public int hashCode() { return Objects.hash(id); } @Override public int compareTo(Student s) { return this.id.compareTo(s.id); } } public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); HashSet<CourseSelection> courseSelectionHashSet = new HashSet<>(); HashSet<String> courseNameSet = new HashSet<>(); HashMap<Student, Boolean> studentScorehashMap = new HashMap<>(); TreeMap<Student, Integer> averageStudentScore = new TreeMap<>(); TreeMap<Course, Integer> courseUsualAverage = new TreeMap<>(); TreeMap<Course, Integer> courseFinalAverage = new TreeMap<>(); TreeMap<Course, Integer> courseTotalAverage = new TreeMap<>(); TreeMap<String, Integer> classTotalAverage = new TreeMap<>(); TreeMap<Course, ArrayList<Float>> scoreWeight = new TreeMap<>(); while (true) { String temp = scanner.nextLine(); if (temp.equals("end")) { break; } String[] s = temp.split(" "); if (s[0].matches("[0-9]{0,100}")) { Student student = new Student(s[0], s[1]); Course course = null; Grade grade = new ExamScore(); ArrayList<Float>weight=new ArrayList<>(); if (s.length >= 5) { int flag = 0; for (int i = 4; i < s.length; i++) { if (!s[i].matches("[0-9]{1,3}")) { System.out.println("wrong format"); flag = 1; break; } else if (Integer.parseInt(s[i]) < 0 || Integer.parseInt(s[i]) > 100) { System.out.println("wrong format"); flag = 1; break; } } if (flag == 1) continue; } if (s[0].length() != 8 || s[1].length() > 10 || s[2].length() > 10 || !s[3].matches("[0-9]{1,3}") || (Integer.parseInt(s[3]) < 0 || Integer.parseInt(s[3]) > 100)) { System.out.println("wrong format"); continue; } if (courseNameSet.contains(s[2])) { for (Course tempCourse : courseUsualAverage.keySet()) { if (tempCourse.name.equals(s[2])) { grade.weight = scoreWeight.get(tempCourse); weight=grade.weight; course = tempCourse; break; } } } if (s.length == 5 && ((Integer.parseInt(s[4]) < 0) || (Integer.parseInt(s[4]) > 100))) { System.out.println("wrong format"); continue; } else if (course != null && course.mode == 2) { if (s.length != grade.weight.size() + 3) { System.out.println(s[0] + " " + s[1] + " " + ": access mode mismatch"); classTotalAverage.put(s[0].substring(0, 6), 0); averageStudentScore.put(student, 0); continue; } } if (!courseNameSet.contains(s[2])) { System.out.println(s[2] + " does not exist"); averageStudentScore.put(student, 0); classTotalAverage.put(s[0].substring(0, 6), 0); continue; } if (s.length == 4 && Objects.requireNonNull(course).mode == 1) { grade = new ExamineGrade(); grade.weight=weight; grade.finalGrade = Integer.parseInt(s[3]); } else if (s.length == 5 && Objects.requireNonNull(course).mode == 0) { grade = new ExamScore(); grade.weight=weight; grade.usualGrade = Integer.parseInt(s[3]); grade.finalGrade = Integer.parseInt(s[4]); } else { assert course != null; if (course.mode == 2) { grade = new ExperimentalScore(); grade.weight=weight; for (int i = 3; i < s.length; i++) { grade.experimentalGrades.add(Integer.parseInt(s[i])); } } } classTotalAverage.put(s[0].substring(0, 6), 0); if ((s.length == 4 && course.mode == 0) || (s.length == 5 && course.mode == 1)) { System.out.println(s[0] + " " + s[1] + " " + ": access mode mismatch"); averageStudentScore.put(student, 0); continue; } averageStudentScore.put(student, 0); CourseSelection courseSelection = new CourseSelection(course, student, grade); courseSelectionHashSet.add(courseSelection); } else { if (!s[1].equals("实验") && s.length != 3 && s.length != 2&&s.length!=5) { System.out.println("wrong format"); continue; } if(s[2].equals("考察")&&s.length>=5){ System.out.println("wrong format"); continue; } if ((s.length == 3) && (s[0].length() > 10 || ((!s[1].equals("必修") && !s[1].equals("选修") && !s[1].equals("实验")) || (!s[2].equals("考试") && !s[2].equals("考察") && !s[2].equals("实验"))))) { System.out.println("wrong format"); continue; } int type = 0; ArrayList<Float> arrayList = new ArrayList<>(); if (s[1].equals("必修")) type = 0; if (s[1].equals("选修")) type = 1; if (s[1].equals("实验")) type = 2; Course course = new Course(s[0], type); int mode = 0; if (s[2].equals("考试")) mode = 0; if (s[2].equals("考察")) mode = 1; if (s[2].equals("实验")) mode = 2; course.mode = mode; if ((course.type == 0 && course.mode == 1) || (course.mode == 2 && course.type != 2) || course.type == 2 && course.mode != 2) { System.out.println(s[0] + " : course type & access mode mismatch"); continue; } if (s[1].equals("实验") && !s[3].matches("[4-9]")) { System.out.println("wrong format"); continue; } else if (s[1].equals("实验") && Integer.parseInt(s[3]) + 4 != s.length) { System.out.println(course.name + " : number of scores does not match"); continue; } else if ((s[1].equals("必修") && (int)(Float.parseFloat(s[3]) + Float.parseFloat(s[4])) != 1)) { System.out.println(course.name + " : weight value error"); continue; } else if (s[1].equals("实验")) { int n = Integer.parseInt(s[3]); float sum = 0; for (int i = 0; i < n; i++) { float tempFloat = Float.parseFloat(s[i + 4]); sum += tempFloat; arrayList.add(tempFloat); } if (sum != 1) { System.out.println(course.name + " : weight value error"); continue; } } else if (s[2].equals("考试")) { arrayList.add(Float.parseFloat(s[3])); arrayList.add(Float.parseFloat(s[4])); } if(courseNameSet.contains(course.name)){ continue; } scoreWeight.put(course, arrayList); courseUsualAverage.put(course, 0); courseFinalAverage.put(course, 0); courseTotalAverage.put(course, 0); courseNameSet.add(s[0]); } } for (Student student : averageStudentScore.keySet()) { List<Integer> list = new ArrayList<>(); for (CourseSelection courseSelection : courseSelectionHashSet) { if (courseSelection.student.id.equals(student.id)) { list.add(courseSelection.grade.getGrade()); } } for (Integer tempScore : list) { averageStudentScore.replace(student, averageStudentScore.get(student) + tempScore); } if (list.size() != 0) averageStudentScore.replace(student, averageStudentScore.get(student) / list.size()); if (list.size() == 0) { studentScorehashMap.put(student, false); System.out.println(student.id + " " + student.name + " " + "did not take any exams"); } else { studentScorehashMap.put(student, true); System.out.println(student.id + " " + student.name + " " + averageStudentScore.get(student)); } } for (Course course : courseUsualAverage.keySet()) { List<Integer> list = new ArrayList<>(); List<Integer> list1 = new ArrayList<>(); List<Integer> list2 = new ArrayList<>(); //平时分 for (CourseSelection courseSelection : courseSelectionHashSet) { if (courseSelection.course.name.equals(course.name)) { list.add(courseSelection.grade.usualGrade); } } //期末分 for (CourseSelection courseSelection : courseSelectionHashSet) { if (courseSelection.course.name.equals(course.name)) { list1.add(courseSelection.grade.finalGrade); } } //综合分 for (CourseSelection courseSelection : courseSelectionHashSet) { if (courseSelection.course.name.equals(course.name)) { list2.add(courseSelection.grade.getGrade()); } } for (Integer tempScore : list) { courseUsualAverage.replace(course, courseUsualAverage.get(course) + tempScore); } for (Integer tempScore : list1) { courseFinalAverage.replace(course, courseFinalAverage.get(course) + tempScore); } for (Integer tempScore : list2) { courseTotalAverage.replace(course, courseTotalAverage.get(course) + tempScore); } if (list.size() != 0) courseUsualAverage.replace(course, courseUsualAverage.get(course) / list.size()); if (list1.size() != 0) courseFinalAverage.replace(course, courseFinalAverage.get(course) / list1.size()); if (list2.size() != 0) courseTotalAverage.replace(course, courseTotalAverage.get(course) / list2.size()); if (list.size() == 0) { System.out.println(course.name + " has no grades yet"); } else { System.out.println(course.name + " " + courseTotalAverage.get(course)); } } for (String classId : classTotalAverage.keySet()) { int sum = 0; boolean flag = false; for (Student student : averageStudentScore.keySet()) { if (student.id.substring(0, 6).equals(classId)) { classTotalAverage.replace(classId, classTotalAverage.get(classId) + averageStudentScore.get(student)); if (studentScorehashMap.get(student)) { flag = true; sum++; } } } if (sum != 0) classTotalAverage.replace(classId, classTotalAverage.get(classId) / sum); if (flag) { System.out.println(classId + " " + classTotalAverage.get(classId)); } else { System.out.println(classId + " " + "has no grades yet"); } } } }
类图：
圈复杂度：
优点：
- 代码结构清晰：代码按照类的组织方式进行了划分，每个类具有清晰的职责。
- 使用了合适的数据结构：HashSet、HashMap、TreeMap等数据结构被恰当地用于存储和组织数据。
- 重写了equals()和hashCode()方法：在Course和CourseSelection类中重写了equals()和hashCode()方法，确保了正确的对象比较和哈希值生成。
- 采用了面向对象的设计：通过定义多个类和使用继承、抽象类等概念，实现了代码的可扩展性和复用性。
缺点：
- 变量命名不规范：代码中存在一些缩写、单个字母的变量命名，降低了代码的可读性和可维护性。
- 魔法数值硬编码：代码中出现一些硬编码的数值，缺乏可读性和可维护性，建议使用有意义的常量或枚举来替代。
- 缺乏注释：代码中没有足够的注释来解释每个类、方法或关键代码段的功能和用途，增加了阅读和理解代码的难度。
- 输入验证不完善：在部分输入验证中存在一些问题，没有覆盖所有可能的错误情况，建议进行更全面的输入验证和异常处理。
踩坑心得
-
搞清楚运算的方法和算法。
- 要清楚每个数据定义的范围。
- 类与类之间的关系以调用逻辑
改进建议
-
根据需求快速了解并设计出相应类图和方法，以及类与类之间的关系。
- 对于算法和题目中的计算要加强理解
总结
-
语言基础：
- 了解Java的基本语法，包括变量、数据类型、运算符、表达式、控制流语句等。
- 学习如何使用类、对象和方法，掌握面向对象编程的概念和原则。
- 熟悉数组的使用和常见操作，了解字符串的处理和常用方法。
- 学习异常处理机制，了解如何处理和抛出异常。
-
核心类库：
- 掌握Java的核心类库，如集合框架（List、Set、Map等）和常用类（String、Math等）的使用。
- 学习输入输出操作，包括文件读写和控制台输入输出。
- 理解Java的日期和时间处理，使用Date、Calendar和新的时间API（java.time包）进行日期时间操作。
- 学习多线程编程，了解线程的创建、同步和通信机制。
-
面向对象编程：
- 深入理解面向对象编程的概念，包括封装、继承、多态等。
- 学习如何设计和实现类、接口和抽象类，理解继承和实现的关系。
- 熟悉设计模式的常用模式，如单例模式、工厂模式、观察者模式等。
-
异常处理和调试：
- 掌握异常处理的概念和使用，使用try-catch语句捕获和处理异常。
- 学习调试技巧，如使用断点进行代码调试，利用调试工具定位和解决问题。
-
输入输出和文件操作：
- 学习使用Java的输入输出流，实现对文件和网络的读写操作。
- 熟悉文件和目录的处理，包括创建、复制、删除和遍历等操作。
-
Java开发工具和环境：
- 了解Java开发环境的搭建和配置，如安装JDK、设置环境变量等。
- 学习使用常见的集成开发环境（IDE），如Eclipse、IntelliJ IDEA等，提高开发效率。
-
编码规范和项目管理：
- 遵循Java编码规范，如命名规范、代码风格等，提高代码的可读性和可维护性。
- 学习使用构建工具（如Maven或Gradle）管理项目依赖和构建过程。
- 熟悉版本控制工具（如Git），实现代码版本管理和团队协作。
