BLOG-2
一、前言
面向对象程序设计（Object-Oriented Programming，简称OOP）是一种编程范式，它以对象作为程序的基本单元，将数据和操作封装在一起。面向对象程序设计的基本概念包括类、对象、继承、多态等。
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类（Class）是面向对象程序设计的基本构建块，它是一种抽象的数据类型，用于描述具有相同属性和行为的对象的集合。类定义了对象的属性（成员变量）和行为（方法）。
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对象（Object）是类的实例化结果，它是具体的、有状态的实体。对象可以根据类的定义，拥有自己的属性值，并能执行类中定义的方法。
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继承（Inheritance）是一种机制，允许在已有类的基础上创建新类，新类可以继承和扩展已有类的属性和方法。继承能够提供代码的重用性和层次化的组织结构。
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多态（Polymorphism）是指同一类型的对象在不同的情况下可以表现出不同的行为。多态性可以通过继承和接口实现，使得程序可以根据上下文选择合适的方法。
面向对象程序设计的优点包括代码的可重用性、可扩展性、易维护性和模块化等。它提供了一种更加灵活和抽象的编程方式，使得程序的设计和实现更加清晰和可管理。在前三次的作业中我主要使用了创建类和对象的知识，并未涉及到继承和多态的有关知识的运用。
二、作业分析
1.菜单计价程序-2
类设计如下：
菜品类：对应菜谱上一道菜的信息。
Dish {
String name;//菜品名称
int unit_price; //单价
int getPrice(int portion)//计算菜品价格的方法，输入参数是点菜的份额（输入数据只能是1/2/3，代表小/中/大份） }
菜谱类：对应菜谱，包含饭店提供的所有菜的信息。
Menu {
Dish[] dishs ;//菜品数组，保存所有菜品信息
Dish searthDish(String dishName)//根据菜名在菜谱中查找菜品信息，返回Dish对象。
Dish addDish(String dishName,int unit_price)//添加一道菜品信息
}
点菜记录类：保存订单上的一道菜品记录
Record {
int orderNum;//序号\
Dish d;//菜品\
int portion;//份额（1/2/3代表小/中/大份）\
int getPrice()//计价，计算本条记录的价格\
}
订单类：保存用户点的所有菜的信息。
Order {
Record[] records；//保存订单上每一道的记录
int getTotalPrice()//计算订单的总价
Record addARecord(int orderNum,String dishName,int portion,int num)//添加一条菜品信息到订单中。
delARecordByOrderNum(int orderNum)//根据序号删除一条记录
findRecordByNum(int orderNum)//根据序号查找一条记录
}代码如下：
import java.util.Scanner; import java.util.*; class Dish{ String name;//菜品名称 int unit_price;//单价 int getPrice(int portion){//计算菜品价格的方法，输入参数是点菜的份额（输入数据只能是1/2/3，代表小/中/大份） int price = 0; if(portion == 1){ price = unit_price; } else if(portion == 2) price = Math.round((float)(unit_price * 1.5)); else if(portion == 3) price = (unit_price * 2); return price; } } class Menu{ Dish[] dishs = new Dish[10];//菜品数组，保存所有菜品信息 int count = 0; Dish searthDish(String dishName){//根据菜名在菜谱中查找菜品信息，返回Dish对象。 Dish temd = null; for(int i = count - 1;i >= 0;i--){ if(dishName.equals(dishs[i].name)){ temd = dishs[i]; break; } } if(temd == null) System.out.println(dishName + " does not exist"); return temd; } Dish addDish(String dishName,int unit_price){//添加一道菜品信息 Dish dish = new Dish(); dish.name = dishName; dish.unit_price = unit_price; count++; return dish; } } class Record{ int orderNum;//序号\\ Dish d = new Dish();//菜品\\ int num = 0; int portion;//份额（1/2/3代表小/中/大份）\\ int getPrice(){//计价，计算本条记录的价格\\ return d.getPrice(portion) * num; } } class Order { Record[] records = new Record[10];//保存订单上每一道的记录 int count = 0;//订单数量 void addARecord(int orderNum,String dishName,int portion,int num){//添加一条菜品信息到订单中 records[count] = new Record(); records[count].d.name = dishName; records[count].orderNum = orderNum; records[count].portion = portion; records[count].num = num; count++; } int delARecordByOrderNum(int orderNum){//根据序号删除一条记录 if(orderNum > count || orderNum <= 0){ System.out.println("delete error;"); return 0; } else return records[orderNum - 1].getPrice(); } } public class Main{ public static void main(String[] args){ Scanner sc = new Scanner(System.in); Menu menu = new Menu(); Order order = new Order(); int j = 0; int l = 0; Dish dish; int count; String temp[]; int prices = 0; int a0,a1,a2,a3; while(true){ String str = sc.nextLine(); temp = str.split(" "); if(str.equals("end")) break; count = temp.length; if(count == 2){ if(temp[1].equals("delete")){ a0 = Integer.parseInt(temp[0]); int c = order.delARecordByOrderNum(a0); prices -= c; } else{ a1 = Integer.parseInt(temp[1]); menu.dishs[j] = menu.addDish(temp[0],a1); j++; } } else if(count == 4){ a0 = Integer.parseInt(temp[0]); a2 = Integer.parseInt(temp[2]); a3 = Integer.parseInt(temp[3]); order.addARecord(a0,temp[1],a2,a3); dish = menu.searthDish(temp[1]); if(dish != null){ order.records[l].d = dish; int c = order.records[l].getPrice(); System.out.println(order.records[l].orderNum + " " + dish.name + " " + c); prices += c; } l++; } } System.out.println(prices); } }
分析：用string接收输入的一行信息，再根据空格分成string数组中的元素，用if语句判断这个数组中有多少个元素来判断用户想要我们做什么。
2.菜单计价系统-3
类设计如下：
菜品类：对应菜谱上一道菜的信息。
Dish {
String name;//菜品名称
int unit_price; //单价
int getPrice(int portion)//计算菜品价格的方法，输入参数是点菜的份额（输入数据只能是1/2/3，代表小/中/大份） }
菜谱类：对应菜谱，包含饭店提供的所有菜的信息。
Menu {
Dish\[\] dishs ;//菜品数组，保存所有菜品信息
Dish searthDish(String dishName)//根据菜名在菜谱中查找菜品信息，返回Dish对象。
Dish addDish(String dishName,int unit_price)//添加一道菜品信息
}
点菜记录类：保存订单上的一道菜品记录
Record {
int orderNum;//序号\\
Dish d;//菜品\\
int portion;//份额（1/2/3代表小/中/大份）\\
int getPrice()//计价，计算本条记录的价格\\
}
订单类：保存用户点的所有菜的信息。
Order {
Record\[\] records；//保存订单上每一道的记录
int getTotalPrice()//计算订单的总价
Record addARecord(int orderNum,String dishName,int portion,int num)//添加一条菜品信息到订单中。
delARecordByOrderNum(int orderNum)//根据序号删除一条记录
findRecordByNum(int orderNum)//根据序号查找一条记录
}
代码如下：
import java.util.Scanner; import java.util.*; class Dish{ String name;//菜品名称 int unit_price;//单价 int getPrice(int portion){//计算菜品价格的方法，输入参数是点菜的份额（输入数据只能是1/2/3，代表小/中/大份） int price = 0; if(portion == 1){ price = unit_price; } else if(portion == 2) price = Math.round((float)(unit_price * 1.5)); else if(portion == 3) price = (unit_price * 2); return price; } } class Menu{ Dish[] dishs = new Dish[10];//菜品数组，保存所有菜品信息 int count = 0; Dish searthDish(String dishName){//根据菜名在菜谱中查找菜品信息，返回Dish对象。 Dish temd = null; for(int i = count - 1;i >= 0;i--){ if(dishName.equals(dishs[i].name)){ temd = dishs[i]; break; } } if(temd == null) System.out.println(dishName + " does not exist"); return temd; } Dish addDish(String dishName,int unit_price){//添加一道菜品信息 Dish dish = new Dish(); dish.name = dishName; dish.unit_price = unit_price; count++; return dish; } } class Record{ int orderNum;//序号\\ Dish d = new Dish();//菜品\\ int num = 0; int portion;//份额（1/2/3代表小/中/大份）\\ int getPrice(){//计价，计算本条记录的价格\\ return d.getPrice(portion) * num; } } class Order { Record[] records = new Record[10];//保存订单上每一道的记录 int count = 0;//订单数量 void addARecord(int orderNum,String dishName,int portion,int num){//添加一条菜品信息到订单中 records[count] = new Record(); records[count].d.name = dishName; records[count].orderNum = orderNum; records[count].portion = portion; records[count].num = num; count++; } int delARecordByOrderNum(int orderNum){//根据序号删除一条记录 if(orderNum > count || orderNum <= 0){ System.out.println("delete error;"); return 0; } else return records[orderNum - 1].getPrice(); } } class Table{ int tableNum; String tableDtime; int year,month,day,week,hh,mm,ss; int sum = 0; Order odt = new Order(); float dis = -1; void Gettottalprice(){ if(dis > 0){ sum = Math.round(sum * dis); System.out.println("table " + tableNum + ": " + sum); } else System.out.println("table " + tableNum + " out of opening hours"); } void AheadProcess(String tableDtime){ this.tableDtime = tableDtime; processTime(); discount(); } void processTime(){ String[] temp = tableDtime.split(" "); tableNum = Integer.parseInt(temp[1]); String[] temp1 = temp[2].split("/"); String[] temp2 = temp[3].split("/"); year = Integer.parseInt(temp1[0]); month = Integer.parseInt(temp1[1]); day = Integer.parseInt(temp1[2]); Calendar c = Calendar.getInstance(); c.set(year, (month-1), day); week = c.get(Calendar.DAY_OF_WEEK); if(week == 1) week = 7; else week--; hh = Integer.parseInt(temp2[0]); mm = Integer.parseInt(temp2[1]); ss = Integer.parseInt(temp2[2]); } void discount(){ if(week >= 1 && week <= 5){ if( (hh >= 17 && hh < 20) || (hh == 20 && mm < 30) || (hh == 20 && mm == 30 && ss == 0)) dis = 0.8F; if( (hh >= 11 && hh <= 13) || (hh == 10 && mm >= 30) || (hh == 14 && mm < 30) || (hh == 14 && mm == 30 && ss == 0)) dis = 0.6F; } else{ if( (hh >= 10 && hh <= 20) || (hh == 9 && mm >= 30) || (hh == 21 && mm < 30) || (hh == 21 && mm == 30 && ss == 0)) dis = 1.0F; } } } public class Main{ public static void main(String[] args){ Scanner sc = new Scanner(System.in); Menu menu = new Menu(); Table[] tablemes = new Table[10]; int j = 0; int l = 0; int k = 0; Dish dish; int cntTable = 0; int count; String[] temp; int a0,a1,a2,a3,a4; while(true){ String st = sc.nextLine(); temp = st.split(" "); if(st.equals("end")) break; count = temp.length; if(count == 2){ if(temp[1].equals("delete")){ a0 = Integer.parseInt(temp[0]); int c = tablemes[cntTable].odt.delARecordByOrderNum(a0); tablemes[cntTable].sum -= c; } else{ a1 = Integer.parseInt(temp[1]); menu.dishs[j] = menu.addDish(temp[0],a1); j++; } } else if(count == 4){ if(temp[0].equals("table")){ cntTable++; l = 0; tablemes[cntTable] = new Table(); tablemes[cntTable].AheadProcess(st); System.out.println("table " + cntTable + ": "); } else{ a0 = Integer.parseInt(temp[0]); a2 = Integer.parseInt(temp[2]); a3 = Integer.parseInt(temp[3]); tablemes[cntTable].odt.addARecord(a0, temp[1],a2 , a3); dish = menu.searthDish(temp[1]); if(dish != null){ tablemes[cntTable].odt.records[l].d = dish; int a = tablemes[cntTable].odt.records[l].getPrice(); System.out.println(tablemes[cntTable].odt.records[l].orderNum + " " + dish.name + " " + a ); tablemes[cntTable].sum += a; } l++; } } else if(count == 5){ a1 = Integer.parseInt(temp[1]); a3 = Integer.parseInt(temp[3]); a4 = Integer.parseInt(temp[4]); tablemes[cntTable].odt.addARecord(a1,temp[2],a3,a4); dish = menu.searthDish(temp[2]); if(dish != null){ tablemes[cntTable].odt.records[l].d.unit_price = dish.unit_price; int b = tablemes[cntTable].odt.records[l].getPrice(); System.out.println(temp[1] + " table " + tablemes[cntTable].tableNum + " pay for table " + temp[0] + " " + b); tablemes[cntTable].sum += b; } l++; } } for(int i = 1;i < cntTable + 1;i++) tablemes[i].Gettottalprice(); } }
分析：用string接收输入的一行信息，再根据空格分成string数组中的元素，用if语句判断这个数组中有多少个元素来判断用户想要我们做什么。和菜单计价系统-2一样，只是多了一个桌号。
3.菜单计价系统-4
类设计如下：
菜品类：对应菜谱上一道菜的信息。
Dish {
String name;//菜品名称
int unit_price; //单价
int getPrice(int portion)//计算菜品价格的方法，输入参数是点菜的份额（输入数据只能是1/2/3，代表小/中/大份） }
菜谱类：对应菜谱，包含饭店提供的所有菜的信息。
Menu {
Dish[] dishs ;//菜品数组，保存所有菜品信息
Dish searthDish(String dishName)//根据菜名在菜谱中查找菜品信息，返回Dish对象。
Dish addDish(String dishName,int unit_price)//添加一道菜品信息
}
点菜记录类：保存订单上的一道菜品记录
Record {
int orderNum;//序号
Dish d;//菜品\\
int portion;//份额（1/2/3代表小/中/大份）
int getPrice()//计价，计算本条记录的价格
}
订单类：保存用户点的所有菜的信息。
Order {
Record[] records；//保存订单上每一道的记录
int getTotalPrice()//计算订单的总价
Record addARecord(int orderNum,String dishName,int portion,int num)//添加一条菜品信息到订单中。
delARecordByOrderNum(int orderNum)//根据序号删除一条记录
findRecordByNum(int orderNum)//根据序号查找一条记录
}
代码如下：
import java.text.ParseException; import java.time.DateTimeException; import java.time.Duration; import java.time.LocalDate; import java.time.LocalDateTime; import java.util.ArrayList; import java.util.Scanner; public class Main{ public static boolean isNumeric(String string){ int intValue; try{ intValue = Integer.parseInt(string); return true; } catch(NumberFormatException e){ return false; } } public static void main(String[] args) throws ParseException{ Menu menu = new Menu(); ArrayList<Table> tables = new ArrayList<Table>(); Scanner input = new Scanner(System.in); String str1 = new String(); int i = 0; int portion = 0, quota = 0; while(true){// 输入菜单 Dish temp = new Dish(); int isRepeat = -1; str1 = input.nextLine(); if(str1.matches("[\\S]* [1-9][\\d]*")){ String[] token = str1.split(" "); temp.name = token[0]; temp.unit_price = Integer.parseInt(token[1]); if(temp.unit_price > 300){ System.out.println(temp.name + " price out of range " + temp.unit_price); continue; } temp.isT = false; isRepeat = menu.searchDish(temp.name); if(isRepeat != -1){ menu.dishs.remove(isRepeat); } menu.dishs.add(temp); } else if(str1.matches("[\\S]* [\\d]* T")){ String[] token = str1.split(" "); temp.name = token[0]; temp.unit_price = Integer.parseInt(token[1]); if(temp.unit_price > 300){ System.out.println(temp.name + " price out of range " + temp.unit_price); continue; } temp.isT = true; if(isRepeat != -1){ menu.dishs.remove(isRepeat); } menu.dishs.add(temp); } else if(str1.equals("end")){ break; } else if(str1.matches("tab.*")){ break; } else{ System.out.println("wrong format"); continue; } } while(!str1.equals("end")){ Table temp = new Table(); boolean isRepeat = false; int repeatNum = 0; if(str1.matches("table.*")){ if(str1.matches("table [1-9][\\d]* [\\d]*/[\\d][\\d]?/[\\d][\\d]? [\\d][\\d]?/[\\d][\\d]?/[\\d][\\d]?")){ String[] token = str1.split(" "); String[] Date = token[2].split("/"); String[] Time = token[3].split("/"); int[] intDate = new int[3]; int[] intTime = new int[3]; for(i = 0; i < 3; i++){ intDate[i] = Integer.parseInt(Date[i]); intTime[i] = Integer.parseInt(Time[i]); } temp.num = Integer.parseInt(token[1]); if(temp.num > 55){ System.out.println(temp.num + " table num out of range"); str1 = input.nextLine(); continue; } try{ temp.time = LocalDateTime.of(intDate[0], intDate[1], intDate[2], intTime[0], intTime[1], intTime[2]); temp.getWeekDay(); } catch(DateTimeException e){ System.out.println(temp.num + " date error"); str1 = input.nextLine(); continue; } if(!(temp.time.isAfter(LocalDateTime.of(2022, 1, 1, 0, 0, 0)) && temp.time.isBefore(LocalDateTime.of(2024, 1, 1, 0, 0, 0)))){ System.out.println("not a valid time period"); str1 = input.nextLine(); continue; } // 判断桌号是否重复 if(temp.isOpen()){ for(i = 0; i < tables.size(); i++){ // 有重复的桌号 if(temp.num == tables.get(i).num && tables.get(i).isOpen()){ Duration duration = Duration.between(temp.time, tables.get(i).time); // 同一天 if(duration.toDays() == 0){ // 在周一到周五 if(temp.weekday > 0 && temp.weekday < 6){ // 在同一时间段 if(temp.time.getHour() < 15 && tables.get(i).time.getHour() < 15){ temp = tables.get(i); isRepeat = true; repeatNum = i; break; } } // 在周末 else{ // 时间相差小于一小时 if(duration.toHours() < 3600){ temp = tables.get(i); repeatNum = i; isRepeat = true; break; } } } } } } if(!isRepeat){ System.out.println("table " + temp.num + ": "); } } else{ System.out.println("wrong format"); str1 = input.nextLine(); continue; } // 本桌开始点菜 while(true){ str1 = input.nextLine(); if(str1.matches("[1-9][\\d]* [\\S]* [\\d] [1-9][\\d]*")){ String[] token = str1.split(" "); portion = Integer.parseInt(token[2]); quota = Integer.parseInt(token[3]); if(temp.order.records.size() > 0){ if(Integer.parseInt( token[0]) <= temp.order.records.get(temp.order.records.size() - 1).orderNum){ System.out.println("record serial number sequence error"); continue; } } if(menu.searchDish(token[1]) == -1){ System.out.println(token[1] + " does not exist"); continue; } if(portion > 3 || portion < 1){ System.out.println(Integer.parseInt(token[0]) + " portion out of range " + portion); continue; } if(quota > 15){ System.out.println(Integer.parseInt(token[0]) + " num out of range " + quota); continue; } temp.od(menu, token[0], token[1], portion, quota); } // 判断是否为删除订单 else if(str1.matches("[1-9][\\d]* delete")){ String[] token = str1.split(" "); temp.order.delARecordByOrderNum(Integer.parseInt(token[0])); } // 判断是否为夹杂菜单 else if(str1.matches("[\\S]* [\\d]*")){ System.out.println("invalid dish"); continue; } else if(str1.matches("[\\S]* [\\d]* T")){ System.out.println("invalid dish"); continue; } // 判断是否为代点 else if(str1.matches("[\\d]* [\\d]* [\\S]* [\\d] [1-9][\\d]*")){ String[] token = str1.split(" "); // 判断代点桌号是否存在 boolean exist = false; for(int j = 0; j < tables.size(); j++){ if(tables.get(j).num == Integer.parseInt(token[0])){ exist = true; break; } } if(exist){ System.out.print(Integer.parseInt(token[1]) + " table " + temp.num + " pay for table " + Integer.parseInt(token[0]) + " "); Record treat = new Record(); treat.d = menu.dishs.get(menu.searchDish(token[2])); portion = Integer.parseInt(token[3]); quota = Integer.parseInt(token[4]); treat.portion = portion; treat.quota = quota; System.out.print(treat.getPrice() + "\n"); temp.sum += treat.getPrice(); } // 若不存在则输出内容 else{ System.out.println("Table number ：" + Integer.parseInt(token[0]) + " does not exist"); } } else if(str1.equals("end")){ break; } else if(str1.matches("ta.*")){ break; } else{ System.out.println("wrong format"); continue; } } } else if(str1.matches("t.*")){ isRepeat = true; temp = tables.get(tables.size()); while(true){ str1 = input.nextLine(); if(str1.matches("[1-9][\\d]* [\\S]* [\\d] [1-9][\\d]*")){ String[] token = str1.split(" "); portion = Integer.parseInt(token[2]); quota = Integer.parseInt(token[3]); // 判断订单号是否由小到大排列 if(temp.order.records.size() > 0){ if(Integer.parseInt( token[0]) <= temp.order.records.get(temp.order.records.size() - 1).orderNum){ System.out.println("record serial number sequence error"); continue; } } if(menu.searchDish(token[1]) == -1){ System.out.println(token[1] + " does not exist"); continue; } if(portion > 3 || portion < 1){ System.out.println(Integer.parseInt(token[0]) + " portion out of range " + portion); continue; } if(quota > 15){ System.out.println(Integer.parseInt(token[0]) + " num out of range " + quota); continue; } temp.od(menu, token[0], token[1], portion, quota); } // 判断是否为删除订单 else if(str1.matches("[1-9][\\d]* delete")){ String[] token = str1.split(" "); temp.order.delARecordByOrderNum(Integer.parseInt(token[0])); } // 判断是否为夹杂菜单 else if(str1.matches("[\\S]* [\\d]*")){ System.out.println("invalid dish"); continue; } else if(str1.matches("[\\S]* [\\d]* T")){ System.out.println("invalid dish"); continue; } // 判断是否为代点 else if(str1.matches("[\\d]* [\\d]* [\\S]* [\\d] [1-9][\\d]*")){ String[] token = str1.split(" "); // 判断代点桌号是否存在 boolean exist = false; for(int j = 0; j < tables.size(); j++){ if(tables.get(j).num == Integer.parseInt(token[0])){ exist = true; break; } } if(exist){ System.out.print(Integer.parseInt(token[1]) + " table " + temp.num + " pay for table " + Integer.parseInt(token[0]) + " "); Record treat = new Record(); treat.d = menu.dishs.get(menu.searchDish(token[2])); portion = Integer.parseInt(token[3]); quota = Integer.parseInt(token[4]); treat.portion = portion; treat.quota = quota; System.out.print(treat.getPrice() + "\n"); temp.sum += treat.getPrice(); } // 若不存在则输出内容 else{ System.out.println("Table number ：" + Integer.parseInt(token[0]) + " does not exist"); } } else if(str1.equals("end")){ break; } else{ System.out.println("wrong format"); continue; } } if(tables.size() != 0){ tables.get(tables.size() - 1).order.records.addAll(temp.order.records); } } else{ str1 = input.nextLine(); continue; } // 本桌点菜结束，进入下一桌 if(isRepeat){ tables.remove(repeatNum); } temp.getSum(); tables.add(temp); } // 最终输出桌号订单信息 for(i = 0; i < tables.size(); i++){ if(tables.get(i).isOpen()){ System.out .println("table " + tables.get(i).num + ": " + tables.get(i).origSum + " " + tables.get(i).sum); } else System.out.println("table " + tables.get(i).num + " out of opening hours"); } } static class Dish{ String name; int unit_price; boolean isT = false; } static class Record{ int orderNum; Dish d; int portion; int quota; boolean isDeleted = false; int getPrice(){ if(portion == 2) return(int) Math.round(1.5 * d.unit_price) * quota; else if(portion == 3) return 2 * d.unit_price * quota; else return d.unit_price * quota; } } static class Menu{ ArrayList<Dish> dishs = new ArrayList<Dish>(); int searchDish(String dishName){ for(int i = 0; i < dishs.size(); i++){ if(dishName.equals(dishs.get(i).name)){ return i; } } return -1; } Dish addDish(String dishName, int unit_price){ Dish newDish = new Dish(); newDish.name = dishName; newDish.unit_price = unit_price; return newDish; } } static class Order{ // Record[] records = new Record[20]; ArrayList<Record> records = new ArrayList<Record>(); Record addARecord(int orderNum, String dishName, int portion, int quota, Menu menu){ Record newRecord = new Record(); newRecord.orderNum = orderNum; newRecord.d = menu.dishs.get(menu.searchDish(dishName)); newRecord.portion = portion; newRecord.quota = quota; System.out.println(newRecord.orderNum + " " + newRecord.d.name + " " + newRecord.getPrice()); return newRecord; } int searchReocrd(String name){ for(int i = 0; i < records.size(); i++){ if(records.get(i).d.name == name){ return i; } } return -1; } boolean delARecordByOrderNum(int orderNum){ int i = 0, flag = 0; for(i = 0; i < records.size(); i++){ if(records.get(i).orderNum == orderNum){ if(records.get(i).isDeleted == false){ records.get(i).isDeleted = true; } else{ System.out.println("deduplication " + orderNum); } flag++; } } if(flag == 0){ System.out.println("delete error;"); return false; } return true; } } static class Table{ Order order = new Order(); int num; LocalDateTime time; int weekday; long sum = 0; long origSum = 0; void od(Menu menu, String str1, String str2, int portion, int quota){ { order.records.add(order.addARecord(Integer.parseInt(str1), str2, portion, quota, menu)); } } void getWeekDay(){ weekday = time.getDayOfWeek().getValue(); } void getSum(){ for(int i = 0; i < order.records.size(); i++){ if(!order.records.get(i).isDeleted){ origSum += order.records.get(i).getPrice(); if(order.records.get(i).d.isT){ if(weekday > 0 && weekday < 6){ sum += Math.round(order.records.get(i).getPrice() * 0.7); } else{ sum += order.records.get(i).getPrice(); } } else{ if(weekday > 0 && weekday < 6){ if(time.getHour() >= 17 && time.getHour() < 20) sum += Math.round(order.records.get(i).getPrice() * 0.8); if(time.getHour() == 20){ if(time.getMinute() <= 30) sum += Math.round(order.records.get(i).getPrice() * 0.8); } if(time.getHour() >= 10 && time.getHour() < 14) sum += Math.round(order.records.get(i).getPrice() * 0.6); if(time.getHour() == 14){ if(time.getMinute() <= 30) sum += Math.round(order.records.get(i).getPrice() * 0.6); } } else sum+=order.records.get(i).getPrice(); } } } } boolean isOpen(){ if(weekday > 0 && weekday < 6){ if(time.getHour() >= 17 && time.getHour() < 20) return true; if(time.getHour() == 20){ if(time.getMinute() <= 30) return true; } if(time.getHour() > 10 && time.getHour() < 14) return true; if(time.getHour() == 10){ if(time.getMinute() >= 30) return true; } if(time.getHour() == 14){ if(time.getMinute() <= 30) return true; } } else{ if(time.getHour() > 9 && time.getHour() < 21) return true; if(time.getHour() == 9){ if(time.getMinute() >= 30) return true; } if(time.getHour() == 21){ if(time.getMinute() <= 30) return true; } } return false; } } }
分析：啊啊啊，好难啊，毁灭吧！
4.菜单计价系统-5
类设计如下：
菜品类：对应菜谱上一道菜的信息。
Dish {
String name;//菜品名称
int unit_price; //单价
int getPrice(int portion)//计算菜品价格的方法，输入参数是点菜的份额（输入数据只能是1/2/3，代表小/中/大份）
}
菜谱类：对应菜谱，包含饭店提供的所有菜的信息。
Menu {
Dish[] dishs ;//菜品数组，保存所有菜品信息
Dish searthDish(String dishName)//根据菜名在菜谱中查找菜品信息，返回Dish对象。
Dish addDish(String dishName,int unit_price)//添加一道菜品信息
}
点菜记录类：保存订单上的一道菜品记录
Record {
int orderNum;//序号\\
Dish d;//菜品\\
int portion;//份额（1/2/3代表小/中/大份）\\
int getPrice()//计价，计算本条记录的价格\\
}
订单类：保存用户点的所有菜的信息。
Order {
Record[] records；//保存订单上每一道的记录
int getTotalPrice()//计算订单的总价
Record addARecord(int orderNum,String dishName,int portion,int num)//添加一条菜品信息到订单中。
delARecordByOrderNum(int orderNum)//根据序号删除一条记录
findRecordByNum(int orderNum)//根据序号查找一条记录
}
代码如下：
import java.util.*; import java.util.Scanner; public class Main{ public static void main(String[] args){ int wrongNum1 = 0; boolean flag; Scanner scanner = new Scanner(System.in); Menu menu = new Menu(); List<Table> tables = new ArrayList<>(); Table currentTable = null; while(scanner.hasNext()){ String line = scanner.nextLine(); if(line.equals("end")){ break; } String[] parts = line.split("\\s+"); if(parts[0].equals("table")){ if( (parts.length != 7) || (!Character.isDigit(parts[1].charAt(0))) || (!parts[2].startsWith(":")) || (!Character.isLetter(parts[3].charAt(0)))){ System.out.println("wrong format"); } int tableNum = Integer.parseInt(parts[1]); String user = parts[3]; String phoneNum = parts[4]; String date = parts[5]; String time = parts[6]; currentTable = new Table(tableNum,user,phoneNum,date,time); tables.add(currentTable); flag = phoneNum.matches("13[356]|18[019]\\d{8}"); if(phoneNum.length() != 11 && !flag) wrongNum1++; } else if(parts[1].equals("delete")){ int orderNum = Integer.parseInt(parts[0]); assert currentTable != null; currentTable.getTotalPrice(); boolean b = currentTable.order.delARecordByOrderNum(orderNum); Record record = currentTable.order.addARecord(orderNum,"",0,-1,-1,menu); record.dish.unit_price = -1; record.isDelOrSue = b; } else if(parts[0].equals("end")){ break; } else{ if(currentTable == null){ if(parts.length == 2){ String dishName = parts[0]; int unit_price = Integer.parseInt(parts[1]); int Flag = 0; menu.addDish(dishName,Flag,unit_price); } if(parts.length == 4){ String dishName = parts[0]; int Flag = 0; int unit_price = Integer.parseInt(parts[2]); if(parts[1].equals("川菜")) Flag = 1; if(parts[1].equals("晋菜")) Flag = 2; if(parts[1].equals("浙菜")) Flag = 3; menu.addDish(dishName,Flag,unit_price); } } else{ if(parts.length == 4){ int tableNum = currentTable.tableNum; int orderNum = Integer.parseInt(parts[0]); String dishName = parts[1]; int portion = Integer.parseInt(parts[2]); int num = Integer.parseInt(parts[3]); for(Table table : tables){ if(table.tableNum == tableNum){ table.order.addARecord(orderNum,dishName,-1,portion,num,menu); break; } } } else if(parts.length == 5){ if(parts[1].length() == 1){ int tableNum = currentTable.tableNum; int orderNum = Integer.parseInt(parts[1]); String dishName = parts[2]; int portion = Integer.parseInt(parts[3]); int num = Integer.parseInt(parts[4]); for(Table table : tables){ if(table.tableNum == tableNum){ Record record = table.order.addARecord(orderNum,dishName, -2,portion,num,menu); record.payTableId = Integer.parseInt(parts[0]); record.payOnBehalf = true; break; } } } if(parts[1].length() != 1){ int tableNum = currentTable.tableNum; int orderNum = Integer.parseInt(parts[0]); String dishName = parts[1]; int tasteNum = Integer.parseInt(parts[2]); int portion = Integer.parseInt(parts[3]); int num = Integer.parseInt(parts[4]); for(Table table : tables){ if(table.tableNum == tableNum){ table.order.addARecord(orderNum,dishName, tasteNum,portion,num,menu); break; } } } } if(parts.length == 6){ int tableNum = currentTable.tableNum; int orderNum = Integer.parseInt(parts[1]); String dishName = parts[2]; int tasteNum = Integer.parseInt(parts[3]); int portion = Integer.parseInt(parts[4]); int num = Integer.parseInt(parts[5]); for(Table table : tables){ if(table.tableNum == tableNum){ Record record = table.order.addARecord(orderNum,dishName, tasteNum,portion,num,menu); record.payTableId = Integer.parseInt(parts[0]); record.payOnBehalf = true; break; } } for(Table table : tables){ if(table.tableNum == tableNum){ Record record = table.order.addARecord(orderNum,dishName, tasteNum,portion,num,menu); record.payTableId = Integer.parseInt(parts[0]); record.payOnBehalf = true; break; } } } } } } ArrayList<Table> objects = new ArrayList<>(); for(Table table : tables){ int totalPrice = table.getTotalPrice(); if(totalPrice != 0 && wrongNum1 == 0){ System.out.println("table " + table.tableNum + ": "); for(Record record : table.order.records){ if(!record.payOnBehalf){ if( record.dish.unit_price != 0 && record.dish.unit_price != -1 && record.tasteNum != -10){ if(record.dish.Flag == 1 && record.tasteNum >= 6){ System.out.println("spicy num out of range :" + record.tasteNum); } else if(record.dish.Flag == 2 && record.tasteNum >= 5){ System.out.println("acidity num out of range :" + record.tasteNum); } else if(record.dish.Flag == 3 && record.tasteNum >= 4){ System.out.println("sweetness num out of range :" + record.tasteNum); } else System.out.println(record.orderNum + " " + record.dish.name + " " + record.dish.getPrice(record.portion) * record.num); } if(record.dish.unit_price == 0){ System.out.println(record.dish.name + " does not exist"); } if(record.dish.unit_price == -1){ if(!record.isDelOrSue || record.isDel){ System.out.println("delete error;"); } } } else{ System.out.println(record.orderNum + " table " + table.tableNum + " pay for table " + record.payTableId + " " + record.dish.getPrice(record.portion) * record.num); } } objects.add(table); } if(totalPrice == 0 && wrongNum1 == 0){ System.out.println("table " + table.tableNum + " out of opening hours"); } } for(Table table : objects){ int totalPrice = table.getTotalPrice(); int totalPrice_yuan = table.getTotalPrice_yuan(); if( totalPrice != 0 && table.getNum1() != 0 && table.getNum2() != 0 && table.getNum3() != 0){ System.out.println("table " + table.tableNum + ": " + totalPrice_yuan + " " + totalPrice + " " + "川菜 " + table.getNum1() + " " + table.getTaste1() + " " + "晋菜 " + table.getNum2() + " " + table.getTaste2() + " " + "浙菜 " + table.getNum3() + " " + table.getTaste3()); } if( totalPrice != 0 && table.getNum1() == 0 && table.getNum2() != 0 && table.getNum3() != 0){ System.out.println("table " + table.tableNum + ": " + totalPrice_yuan + " " + totalPrice + " " + "晋菜 " + table.getNum2() + " " + table.getTaste2() + " " + "浙菜 " + table.getNum3() + " " + table.getTaste3()); } if( totalPrice != 0 && table.getNum1() != 0 && table.getNum2() == 0 && table.getNum3() != 0){ System.out.println("table " + table.tableNum + ": " + totalPrice_yuan + " " + totalPrice + " " + "川菜 " + table.getNum1() + " " + table.getTaste1() + " " + "浙菜 " + table.getNum3() + " " + table.getTaste3()); } if( totalPrice != 0 && table.getNum1() != 0 && table.getNum2() != 0 && table.getNum3() == 0){ System.out.println("table " + table.tableNum + ": " + totalPrice_yuan + " " + totalPrice + " " + "川菜 " + table.getNum1() + " " + table.getTaste1() + " " + "晋菜 " + table.getNum2() + " " + table.getTaste2()); } if( totalPrice != 0 && table.getNum1() == 0 && table.getNum2() == 0 && table.getNum3() != 0){ System.out.println("table " + table.tableNum + ": " + totalPrice_yuan + " " + totalPrice + " " + "浙菜 " + table.getNum3() + " " + table.getTaste3()); } if( totalPrice != 0 && table.getNum1() == 0 && table.getNum2() != 0 && table.getNum3() == 0){ System.out.println("table " + table.tableNum + ": " + totalPrice_yuan + " " + totalPrice + " " + "晋菜 " + table.getNum2() + " " + table.getTaste2()); } if( totalPrice != 0 && table.getNum1() != 0 && table.getNum2() == 0 && table.getNum3() == 0){ System.out.println("table " + table.tableNum + ": " + totalPrice_yuan + " " + totalPrice + " " + "川菜 " + table.getNum1() + " " + table.getTaste1()); } if( totalPrice != 0 && table.getNum1() == 0 && table.getNum2() == 0 && table.getNum3() == 0){ System.out.println("table " + table.tableNum + ": " + totalPrice_yuan + " " + totalPrice + ""); } } int NUM; NUM = objects.size(); objects.get(0).Flag = 0; for(int m = 0;m < NUM;m++){ objects.get(m).price_user = objects.get(m).getTotalPrice(); objects.get(m).Flag = -1; } for(int i = 0;i < NUM;i++){ for(int j =(i + 1);j < NUM;j++){ if(objects.get(i).Flag == 1){ break; } if( objects.get(i).user.equals(objects.get(j).user)){ objects.get(i).price_user += objects.get(j).getTotalPrice(); objects.get(j).Flag = 1; } } } for(int n = 8;n > 0;n--){ for(int l = 0;l < NUM;l++){ if( objects.get(l).user.length() == n && objects.get(l).Flag == -1){ System.out.println(objects.get(l).user + " " + objects.get(l).phoneNum + " " + objects.get(l).price_user); } } } } } class Dish{ String name; int Flag; int unit_price; public Dish(String name,int Flag,int unit_price){ this.name = name; this.unit_price = unit_price; this.Flag = Flag; } public int getPrice(int portion){ double price = 0.0; if(portion == 1) price = unit_price; else if(portion == 2) price = unit_price * 1.5; else if(portion == 3) price = unit_price * 2.0; return(int) Math.round(price); } } class Menu{ Map<String,Dish> dishMap = new HashMap<>(); public Dish searchDish(String dishName){ return dishMap.get(dishName); } public Dish addDish(String dishName,int Flag,int unit_price){ Dish dish = new Dish(dishName,Flag,unit_price); dishMap.put(dishName,dish); return dish; } } class Record{ int orderNum; Dish dish; int tasteNum; int portion; int num; boolean isDel = false; boolean isDelOrSue = false; boolean payOnBehalf = false; int payTableId; public Record(int orderNum,Dish dish,int tasteNum,int portion,int num){ this.orderNum = orderNum; this.dish = dish; this.portion = portion; this.num = num; this.tasteNum = tasteNum; } public int getPrice(){ return !isDel?dish.getPrice(portion) * num:0; } public int getTasteNum(){ return !isDel?tasteNum:-1; } } class Order{ List<Record> records = new ArrayList<>(); public int getNum1(){ int Num1 = 0; for(Record record : records){ if( record.dish.Flag == 1 && record.tasteNum <= 5 && record.getTasteNum() >= 0){ Num1 += record.num; } } return Num1; } public int getNum2(){ int Num2 = 0; for(Record record : records){ if( record.dish.Flag == 2 && record.tasteNum <= 4 && record.getTasteNum() >= 0){ Num2 += record.num; } } return Num2; } public int getNum3(){ int Num3 = 0; for(Record record : records){ if( record.dish.Flag == 3 && record.tasteNum <= 3 && record.getTasteNum() >= 0){ Num3 += record.num; } } return Num3; } public int getTasteNum1(){ int Num1 = 0; double getTasteNum1 = 0; for(Record record : records){ if( record.dish.Flag == 1 && record.tasteNum <= 5 && record.getTasteNum() >= 0){ Num1 += record.num; getTasteNum1 += record.getTasteNum() * record.num; } } getTasteNum1 = getTasteNum1 / Num1; return (int)Math.round(getTasteNum1); } public int getTasteNum2(){ int Num2 = 0; double getTasteNum2 = 0; for(Record record : records){ if( record.dish.Flag == 2 && record.tasteNum <= 4 && record.getTasteNum() >= 0){ Num2 += record.num; getTasteNum2 += record.getTasteNum() * record.num; } } getTasteNum2 = getTasteNum2 / Num2; return (int)Math.round(getTasteNum2); } public int getTasteNum3(){ int Num3 = 0; double getTasteNum3 = 0; for(Record record : records){ if( record.dish.Flag == 3 && record.tasteNum <= 3 && record.getTasteNum() >= 0){ Num3 += record.num; getTasteNum3 += record.getTasteNum() * record.num; } } getTasteNum3 = getTasteNum3 / Num3; return (int)Math.round(getTasteNum3); } public Record addARecord(int orderNum,String dishName,int tasteNum,int portion,int num,Menu menu){ Dish dish = menu.searchDish(dishName); if(dish == null || dish.unit_price == -1){ dish = menu.addDish(dishName,0,0); } Record record = new Record(orderNum,dish,tasteNum,portion,num); records.add(record); return record; } public boolean delARecordByOrderNum(int orderNum){ for(Record record1 : records){ if( record1.orderNum == orderNum){ record1.isDel = true; record1.isDelOrSue = true; return true; } } System.out.println("delete error;"); return false; } } class Table{ int Flag; int price_user; int tableNum; String user; String phoneNum; String date; String time; Order order = new Order(); public Table(int tableNum,String user,String phoneNum,String date,String time){ this.tableNum = tableNum; this.user = user; this.phoneNum = phoneNum; this.date = date; this.time = time; } public String getTaste1(){ int TasteNum1 = order.getTasteNum1(); if(TasteNum1 == 0){ return "不辣"; } if(TasteNum1 == 1){ return "微辣"; } if(TasteNum1 == 2){ return "稍辣"; } if(TasteNum1 == 3){ return "辣"; } if(TasteNum1 == 4){ return "很辣"; } if(TasteNum1 == 5){ return "爆辣"; } return date; } public String getTaste2(){ int TasteNum2 = order.getTasteNum2(); if(TasteNum2 == 0){ return "不酸"; } if(TasteNum2 == 1){ return "微酸"; } if(TasteNum2 == 2){ return "稍酸"; } if(TasteNum2 == 3){ return "酸"; } if(TasteNum2 == 4){ return "很酸"; } return date; } public String getTaste3(){ int TasteNum3 = order.getTasteNum3(); if(TasteNum3 == 0){ return "不甜"; } if(TasteNum3 == 1){ return "微甜"; } if(TasteNum3 == 2){ return "稍甜"; } if(TasteNum3 == 3){ return "甜"; } return date; } public int getNum1(){ return order.getNum1(); } public int getNum2(){ return order.getNum2(); } public int getNum3(){ return order.getNum3(); } public double getDiscount1(){ double discount1 = 1.0; String weekday = getWeekday(date); if(time.contains("/")){ time = time.replaceAll("/",":"); String[] timeParts = time.split(":"); if(timeParts[0].length() < 2){ timeParts[0] = "0" + timeParts[0]; } time= String.join(":",timeParts); } if(weekday.equals("Saturday") || weekday.equals("Sunday")){ if(!isOpeningTime(time)){ return 0; } } else if(weekday.equals("Monday") || weekday.equals("Tuesday") || weekday.equals("Wednesday") || weekday.equals("Thursday") || weekday.equals("Friday")){ if(isOpeningTime(time)){ if( time.compareTo("10:30:00") >= 0 && time.compareTo("14:30:00") <= 0){ discount1 = 0.6; } else if(time.compareTo("17:00:00") >= 0 && time.compareTo("20:30:00") <= 0){ discount1 = 0.8; } else{ return 0; } } } return discount1; } public double getdiscount2(){ double discount2 = 1.0; String weekday = getWeekday(date); if(time.contains("/")){ time = time.replaceAll("/",":"); String[] timeParts = time.split(":"); if(timeParts[0].length() < 2){ timeParts[0] = "0" + timeParts[0]; } time= String.join(":",timeParts); } if( weekday.equals("Saturday") || weekday.equals("Sunday")){ if(!isOpeningTime(time)){ return 0; } } else if(weekday.equals("Monday") || weekday.equals("Tuesday") || weekday.equals("Wednesday") || weekday.equals("Thursday") || weekday.equals("Friday")){ if(isOpeningTime(time)){ if( time.compareTo("10:30:00") >= 0 && time.compareTo("14:30:00") <= 0){ discount2 = 0.7; } else if(time.compareTo("17:00:00") >= 0 && time.compareTo("20:30:00") <= 0){ discount2 = 0.7; } else{ return 0; } } } return discount2; } public int getTotalPrice(){ int totalPrice; int totalPrice1 = 0; int totalPrice2 = 0; for(Record record : order.records){ if( record.dish.Flag == 0){ totalPrice1 += (int)Math.round(record.getPrice()*getDiscount1()); } if( (record.dish.Flag == 1 && record.tasteNum <= 5) || (record.dish.Flag == 2 && record.tasteNum <= 4) || (record.dish.Flag == 3 && record.tasteNum <= 3)){ totalPrice2 += (int)Math.round(record.getPrice()*getdiscount2()); } } totalPrice = totalPrice1 + totalPrice2; return totalPrice; } public int getTotalPrice_yuan(){ int totalPrice_yuan; int totalPrice1_yuan = 0; int totalPrice2_yuan = 0; for(Record record : order.records){ if( record.dish.Flag == 0){ totalPrice1_yuan += Math.round(record.getPrice()); } if( (record.dish.Flag == 1 && record.tasteNum <=5 ) || (record.dish.Flag == 2 && record.tasteNum <=4 ) || (record.dish.Flag == 3 && record.tasteNum <=3)){ totalPrice2_yuan += Math.round(record.getPrice()); } } totalPrice_yuan = totalPrice1_yuan + totalPrice2_yuan; return totalPrice_yuan; } private String getWeekday(String date){ String[] parts = date.split("/"); int year = Integer.parseInt(parts[0]); int month = Integer.parseInt(parts[1]); int day = Integer.parseInt(parts[2]); Calendar calendar = Calendar.getInstance(); calendar.set(year,month - 1,day); int weekdayIndex = calendar.get(Calendar.DAY_OF_WEEK) - 1; String[] weekdays = {"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"}; return weekdays[weekdayIndex]; } private boolean isOpeningTime(String time){ return time.compareTo("09:30:00") >= 0 && time.compareTo("21:30:00") <= 0; } }
分析：桌号识别格式那个快疯了，用if语句写考虑的东西太多了，放弃了。
5.期中考试
（1）测验1-圆类设计
代码如下：
import java.util.Scanner; import java.lang.Math; public class Main{ public static void main(String[] args){ Scanner sc = new Scanner(System.in); double r = sc.nextDouble(); if(r <= 0){ System.out.println("Wrong Format"); return; } else{ double s = Math.PI * Math.pow(r,2); System.out.println(String.format("%.2f",s)); } } }
分析：没有用类，π我一开始是自己打的数字，输入多少位都有一个答案不对，最后用math函数才对的。
（2）测验2-类结构设计
代码如下：
import java.util.Scanner; import java.lang.Math; public class Main{ public static void main(String[] args){ Scanner sc = new Scanner(System.in); double x1 = sc.nextDouble(); double y1 = sc.nextDouble(); double x2 = sc.nextDouble(); double y2 = sc.nextDouble(); double s = (x2 - x1) * (y2 - y1); System.out.println(String.format("%.2f",Math.abs(s))); } }
分析：也没有用类，就是一开始没想到要用绝对值，导致有几个答案错误，后面加上绝对值就过了。
（3）测验3-继承与多态
代码如下：
import java.util.Scanner; import java.lang.Math; public class Main{ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); int choice = input.nextInt(); switch(choice) { case 1://Circle double radiums = input.nextDouble(); if(radiums <= 0){ System.out.println("Wrong Format"); return; } else{ double s = Math.PI * Math.pow(radiums,2); System.out.println(String.format("%.2f",s)); } case 2://Rectangle double x1 = input.nextDouble(); double y1 = input.nextDouble(); double x2 = input.nextDouble(); double y2 = input.nextDouble(); double s = (x2 - x1) * (y2 - y1); System.out.println(String.format("%.2f",Math.abs(s))); break; } } }
分析：还是没有用类，题目上还给了部分代码，把上两题的部分代码复制过来就直接过了。
（4）抽象类与接口
代码如下：
import java.util.Scanner; import java.lang.Math; public class Main{ public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in); int choice = input.nextInt(); while(true){ int choice = input.nextInt(); switch(choice) { case 0:return;break; case 1://Circle double radiums = input.nextDouble(); if(radiums <= 0){ System.out.println("Wrong Format"); } else{ double s = Math.PI * Math.pow(radiums,2); System.out.println(String.format("%.2f",s)); } case 2://Rectangle double x1 = input.nextDouble(); double y1 = input.nextDouble(); double x2 = input.nextDouble(); double y2 = input.nextDouble(); double s = (x2 - x1) * (y2 - y1); System.out.println(String.format("%.2f",Math.abs(s))); break; } } } }
分析：编译没过。当时时间还剩二十多分钟，但我的电脑只剩10%的电了，急忙改了一下，思路是用while函数循环接收choice并执行switch语句，用double数组记录结果，循环结束后对double数组中的元素进行排序然后输出。没错，还是没用类（doge）。
三、总结：
通过完成这三次pta的作业，我发现我写代码的时候还是惯用C语言的思维，并且是面向结果编程而不是面向对象编程，这是个很大的问题。
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