实验4
实验任务2
Gradecalc.hpp代码
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#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <iomanip>
using std::vector;
using std::string;
using std::cin;
using std::cout;
using std::endl;
class GradeCalc: public vector<int> {
public:
GradeCalc(const string &cname, int size);
void input(); // 录入成绩
void output() const; // 输出成绩
void sort(bool ascending = false); // 排序 (默认降序)
int min() const; // 返回最低分
int max() const; // 返回最高分
float average() const; // 返回平均分
void info(); // 输出课程成绩信息
private:
void compute(); // 成绩统计
private:
string course_name; // 课程名
int n; // 课程人数
vector<int> counts = vector<int>(5, 0); // 保存各分数段人数（[0, 60), [60, 70), [70, 80), [80, 90), [90, 100]
vector<double> rates = vector<double>(5, 0); // 保存各分数段比例
};
GradeCalc::GradeCalc(const string &cname, int size): course_name{cname}, n{size} {}
void GradeCalc::input() {
int grade;
for(int i = 0; i < n; ++i) {
cin >> grade;
this->push_back(grade);
}
}
void GradeCalc::output() const {
for(auto ptr = this->begin(); ptr != this->end(); ++ptr)
cout << *ptr << " ";
cout << endl;
}
void GradeCalc::sort(bool ascending) {
if(ascending)
std::sort(this->begin(), this->end());
else
std::sort(this->begin(), this->end(), std::greater<int>());
}
int GradeCalc::min() const {
return *std::min_element(this->begin(), this->end());
}
int GradeCalc::max() const {
return *std::max_element(this->begin(), this->end());
}
float GradeCalc::average() const {
return std::accumulate(this->begin(), this->end(), 0) * 1.0 / n;
}
void GradeCalc::compute() {
for(int grade: *this) {
if(grade < 60)
counts.at(0)++;
else if(grade >= 60 && grade < 70)
counts.at(1)++;
else if(grade >= 70 && grade < 80)
counts.at(2)++;
else if(grade >= 80 && grade < 90)
counts.at(3)++;
else if(grade >= 90)
counts.at(4)++;
}
for(int i = 0; i < rates.size(); ++i)
rates.at(i) = counts.at(i) * 1.0 / n;
}
void GradeCalc::info() {
cout << "课程名称:\t" << course_name << endl;
cout << "排序后成绩: \t";
sort(); output();
cout << "最高分:\t" << max() << endl;
cout << "最低分:\t" << min() << endl;
cout << "平均分:\t" << std::fixed << std::setprecision(2) << average() << endl;
compute(); // 统计各分数段人数、比例
vector<string> tmp{"[0, 60) ", "[60, 70)", "[70, 80)","[80, 90)", "[90, 100]"};
for(int i = tmp.size()-1; i >= 0; --i)
cout << tmp[i] << "\t: " << counts[i] << "人\t"
<< std::fixed << std::setprecision(2) << rates[i]*100 << "%" << endl;
}
task2.cpp代码
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#include "GradeCalc.hpp"
#include <iomanip>
void test() {
int n;
cout << "输入班级人数: ";
cin >> n;
GradeCalc c1("OOP", n);
cout << "录入成绩: " << endl;;
c1.input();
cout << "输出成绩: " << endl;
c1.output();
cout << string(20, '*') + "课程成绩信息" + string(20, '*') << endl;
c1.info();
}
int main() {
test();
}
运行结果：
问题1：存储在其继承的基类vector中；通过vector中自带的各种接口；
问题2：取平均；有影响；将其转化为浮点数；
问题3：输入内容没有进行约束和规范
实验任务3
Gradecalc.hpp代码
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#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <iomanip>
using std::vector;
using std::string;
using std::cin;
using std::cout;
using std::endl;
class GradeCalc {
public:
GradeCalc(const string &cname, int size);
void input(); // 录入成绩
void output() const; // 输出成绩
void sort(bool ascending = false); // 排序 (默认降序)
int min() const; // 返回最低分
int max() const; // 返回最高分
float average() const; // 返回平均分
void info(); // 输出课程成绩信息
private:
void compute(); // 成绩统计
private:
string course_name; // 课程名
int n; // 课程人数
vector<int> grades; // 课程成绩
vector<int> counts = vector<int>(5, 0); // 保存各分数段人数（[0, 60), [60, 70), [70, 80), [80, 90), [90, 100]
vector<double> rates = vector<double>(5, 0); // 保存各分数段比例
};
GradeCalc::GradeCalc(const string &cname, int size): course_name{cname}, n{size} {}
void GradeCalc::input() {
int grade;
for(int i = 0; i < n; ++i) {
cin >> grade;
grades.push_back(grade);
}
}
void GradeCalc::output() const {
for(int grade: grades)
cout << grade << " ";
cout << endl;
}
void GradeCalc::sort(bool ascending) {
if(ascending)
std::sort(grades.begin(), grades.end());
else
std::sort(grades.begin(), grades.end(), std::greater<int>());
}
int GradeCalc::min() const {
return *std::min_element(grades.begin(), grades.end());
}
int GradeCalc::max() const {
return *std::max_element(grades.begin(), grades.end());
}
float GradeCalc::average() const {
return std::accumulate(grades.begin(), grades.end(), 0) * 1.0 / n;
}
void GradeCalc::compute() {
for(int grade: grades) {
if(grade < 60)
counts.at(0)++;
else if(grade >= 60 && grade < 70)
counts.at(1)++;
else if(grade >= 70 && grade < 80)
counts.at(2)++;
else if(grade >= 80 && grade < 90)
counts.at(3)++;
else if(grade >= 90)
counts.at(4)++;
}
for(int i = 0; i < rates.size(); ++i)
rates.at(i) = counts.at(i) *1.0 / n;
}
void GradeCalc::info() {
cout << "课程名称:\t" << course_name << endl;
cout << "排序后成绩: \t";
sort(); output();
cout << "最高分:\t" << max() << endl;
cout << "最低分:\t" << min() << endl;
cout << "平均分:\t" << std::fixed << std::setprecision(2) << average() << endl;
compute(); // 统计各分数段人数、比例
vector<string> tmp{"[0, 60) ", "[60, 70)", "[70, 80)","[80, 90)", "[90, 100]"};
for(int i = tmp.size()-1; i >= 0; --i)
cout << tmp[i] << "\t: " << counts[i] << "人\t"
<< std::fixed << std::setprecision(2) << rates[i]*100 << "%" << endl;
}
task3.cpp代码
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#include "GradeCalc.hpp"
#include <iomanip>
void test() {
int n;
cout << "输入班级人数: ";
cin >> n;
GradeCalc c1("OOP", n);
cout << "录入成绩: " << endl;;
c1.input();
cout << "输出成绩: " << endl;
c1.output();
cout << string(20, '*') + "课程成绩信息" + string(20, '*') << endl;
c1.info();
}
int main() {
test();
}
运行结果：
问题1：存储在类本身的vector成员中；直接访问私有成员grade；
问题2：想要在已有类基础上新增功能或改造既可以通过继承的方式，也可以使用组合类
实验任务4
task4_1.cpp代码
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#include <iostream>
#include <string>
#include <limits>
using namespace std;
void test1() {
string s1, s2;
cin >> s1 >> s2; // cin: 从输入流读取字符串, 碰到空白符(空格/回车/Tab)即结束
cout << "s1: " << s1 << endl;
cout << "s2: " << s2 << endl;
}
void test2() {
string s1, s2;
getline(cin, s1); // getline(): 从输入流中提取字符串，直到遇到换行符
getline(cin, s2);
cout << "s1: " << s1 << endl;
cout << "s2: " << s2 << endl;
}
void test3() {
string s1, s2;
getline(cin, s1, ' '); //从输入流中提取字符串，直到遇到指定分隔符
getline(cin, s2);
cout << "s1: " << s1 << endl;
cout << "s2: " << s2 << endl;
}
int main() {
cout << "测试1: 使用标准输入流对象cin输入字符串" << endl;
test1();
cout << endl;
cin.ignore(numeric_limits<streamsize>::max(), '\n');
cout << "测试2: 使用函数getline()输入字符串" << endl;
test2();
cout << endl;
cout << "测试3: 使用函数getline()输入字符串, 指定字符串分隔符" << endl;
test3();
}
运行结果：
问题1：
用于跳过用户用于结束输入的换行，使得getline()不会在识别到' '后又立刻识别到'\n'导致第二个字符串无法被读取。
task4_2代码
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#include <iostream>
#include <string>
#include <vector>
#include <limits>
using namespace std;
void output(const vector<string> &v) {
for(auto &s: v)
cout << s << endl;
}
void test() {
int n;
while(cout << "Enter n: ", cin >> n) {
vector<string> v1;
for(int i = 0; i < n; ++i) {
string s;
cin >> s;
v1.push_back(s);
}
cout << "output v1: " << endl;
output(v1);
cout << endl;
}
}
int main() {
cout << "测试: 使用cin多组输入字符串" << endl;
test();
}
运行结果：
task4_3代码
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#include <iostream>
#include <string>
#include <vector>
#include <limits>
using namespace std;
void output(const vector<string> &v) {
for(auto &s: v)
cout << s << endl;
}
void test() {
int n;
while(cout << "Enter n: ", cin >> n) {
cin.ignore(numeric_limits<streamsize>::max(), '\n');
vector<string> v2;
for(int i = 0; i < n; ++i) {
string s;
getline(cin, s);
v2.push_back(s);
}
cout << "output v2: " << endl;
output(v2);
cout << endl;
}
}
int main() {
cout << "测试: 使用函数getline()多组输入字符串" << endl;
test();
}
运行结果：
问题2：
同上。
实验任务5
grm.hpp代码
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#include<iostream>
using namespace std;
template<typename T>
class GameResourceManager{
public:
GameResourceManager(T x=0);
T get();
void update(T x);
private:
T resource;
};
template<typename T>
GameResourceManager<T>::GameResourceManager(T x){
resource=x;
}
template<typename T>
T GameResourceManager<T>::get(){
return resource;
}
template<typename T>
void GameResourceManager<T>::update(T x){
resource+=x;
}
task5.cpp代码
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#include "grm.hpp"
#include <iostream>
using std::cout;
using std::endl;
void test1() {
GameResourceManager<float> HP_manager(99.99);
cout << "当前生命值: " << HP_manager.get() << endl;
HP_manager.update(9.99);
cout << "增加9.99生命值后, 当前生命值: " << HP_manager.get() << endl;
HP_manager.update(-999.99);
cout <<"减少999.99生命值后, 当前生命值: " << HP_manager.get() << endl;
}
void test2() {
GameResourceManager<int> Gold_manager(100);
cout << "当前金币数量: " << Gold_manager.get() << endl;
Gold_manager.update(50);
cout << "增加50个金币后, 当前金币数量: " << Gold_manager.get() << endl;
Gold_manager.update(-99);
cout <<"减少99个金币后, 当前金币数量: " << Gold_manager.get() << endl;
}
int main() {
cout << "测试1: 用float类型对类模板GameResourceManager实例化" << endl;
test1();
cout << endl;
cout << "测试2: 用int类型对类模板GameResourceManager实例化" << endl;
test2();
}
运行结果：
实验任务6
info.hpp代码
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#include<iostream>
#include<string>
#include<vector>
#include<iomanip>
using namespace std;
class info{
public:
info(string na,string co,string ci,int n);
void display() const;
private:
string name,contact,city;
int n;
};
info::info(string na,string co,string ci,int n):name{na},contact{co},city{ci}{
this->n=n;
}
void info::display() const{
cout<<left<<setw(16)<<"昵称："<<name<<endl;
cout<<left<<setw(16)<<"联系方式："<<contact<<endl;
cout<<left<<setw(16)<<"所在城市："<<city<<endl;
cout<<left<<setw(16)<<"预定人数"<<n<<endl;
for(int i=0;i<30;i++){
cout<<"-";
}
cout<<endl;
}
task6.cpp代码
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#include<iostream>
#include<string>
#include<vector>
#include<iomanip>
#include"info.hpp"
int main(){
const int capacity=100;
vector<info> audience_list;
int sum=0;
string name,contact,city;
int num;
cout<<"录入用户信息："<<endl<<endl;
cout<<left<<setw(16)<<"昵称"<<setw(16)<<"联系方式（邮箱/手机号）"<<setw(16)<<"所在城市"<<setw(16)<<"预定参加人数"<<endl;
while(cin>>name){
if(name=="finish"){
break;
}
cin>>contact>>city>>num;
if(num>(capacity-sum)){
cout<<"对不起，只剩"<<capacity-sum<<"个位置。" <<endl;
cout<<"1.输入u，更新（update）预定信息"<<endl;
cout<<"2.输入q，推出预定"<<endl;
cout<<"你的选择：";
char c;
cin>>c;
if(c=='u'){
cout<<"请重新输入预定信息："<<endl;
continue;
}
else if(c=='q'){
return 0;
}
}
info x(name,contact,city,num);
audience_list.push_back(x);
sum+=num;
if(sum==capacity){
break;
}
}
cout<<"截至目前，一共有"<<sum<<"位听众预约。预约听众信息如下："<<endl;
for(int i=0;i<30;i++){
cout<<"-";
}
cout<<endl;
for(auto i:audience_list){
i.display();
}
}
运行结果：
实验任务7
date.h代码
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#pragma once
class Date {
private:
int year;
int month;
int day;
int totalDays;
public:
Date(int year, int month, int day);
int getYear()const { return year; }
int getMonth()const { return month; }
int getDay()const { return day; }
int getMaxDay()const;
bool isLeapYear()const {
return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
}
void show() const;
int distance(const Date& date)const {
return totalDays - date.totalDays;
}
};
date.cpp代码
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#include"date.h"
#include<iostream>
#include<cstdlib>
using namespace std;
namespace {
const int DAYS_BEFIRE_MONTH[] = { 0,31,59,90,120,151,181,212,243,273,304 ,334,365 };
}
Date::Date(int year, int month, int day) :year(year), month(month), day(day) {
if (day <= 0 || day > getMaxDay()) {
cout << "Invalid date: ";
show();
cout << endl;
exit(1);
}
int years = year - 1;
totalDays = years * 365 + years / 4 - years / 100 + years / 400 + DAYS_BEFIRE_MONTH[month - 1] + day;
if (isLeapYear() && month > 2) totalDays++;
}
int Date::getMaxDay()const {
if (isLeapYear() && month == 2)
return 29;
else return DAYS_BEFIRE_MONTH[month] - DAYS_BEFIRE_MONTH[month - 1];
}
void Date::show()const {
cout << getYear() << "-" << getMonth() << "-" << getDay();
}
accumulator.h代码
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#pragma once
#include "date.h"
class Accumulator {
private:
Date lastDate;
double value;
double sum;
public:
Accumulator(const Date&date,double value):lastDate(date),value(value),sum{0}{}
double getSum(const Date& date) const {
return sum + value * date.distance(lastDate);
}
void change(const Date& date, double value) {
sum = getSum(date);
lastDate = date;
this->value = value;
}
void reset(const Date& date, double value) {
lastDate = date;
this->value;
sum = 0;
}
};
account.h代码
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#pragma once
#include"date.h"
#include"accumulator.h"
#include<string>
using namespace std;
class Account {
private:
string id;
double balance;
static double total;
protected:
Account(const Date& date, const string &id);
void record(const Date& date, double amount, const string& desc);
void error(const string& msg) const;
public:const string& getId() { return id; }
double getBalance()const { return balance; }
static double getTotal() { return total; }
void show()const;
};
class SavingsAccount:public Account {
private:
Accumulator acc;
double rate;
public:
SavingsAccount(const Date& date, const string& id, double rate);
double getRate() const { return rate; }
void deposit(const Date& date, double amount, const string& desc);
void withdraw(const Date& date, double amount, const string& desc);
void settle(const Date& date);
};
class CreditAccount :public Account {
private:
Accumulator acc;
double credit;
double rate;
double fee;
double getDebt()const {
double balance = getBalance();
return(balance < 0 ? balance : 0);
}
public:CreditAccount(const Date& date, const string& id, double credit, double rate, double fee);
double getCredit()const { return credit; }
double getRate()const { return rate; }
double getFee() const { return fee; }
double getAvailableCredit()const {
if (getBalance() < 0)return credit + getBalance();
else return credit;
}
void deposit(const Date& date, double amount, const string& desc);
void withdraw(const Date& date, double amount, const string& desc);
void settle(const Date& date);
void show()const;
};
account.cpp代码
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accumulator.cpp
#include "account.h"
#include <cmath>
#include<iostream>
using namespace std;
double Account::total = 0;
Account::Account(const Date& date, const string& id) :id(id), balance(0) {
date.show();
cout << "\t#" << id << "created" << endl;
}
void Account::record(const Date& date, double amount, const string& desc) {
amount = floor(amount * 100 + 0.5) / 100;
balance += amount;
total += amount;
date.show();
cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
}
void Account::show()const { cout << id << "\tBalance:" << balance; }
void Account::error(const string& msg)const {
cout << "Error(#" << id << "):" << msg << endl;
}
SavingsAccount::SavingsAccount(const Date&date,const string &id,double rate):Account(date,id),rate(rate),acc(date,0){}
void SavingsAccount::deposit(const Date& date, double amount, const string& desc) {
record(date, amount, desc);
acc.change(date, getBalance());
}
void SavingsAccount::withdraw(const Date& date, double amount, const string& desc) {
if (amount > getBalance()) {
error("not enough money");
}
else {
record(date, -amount, desc);
acc.change(date, getBalance());
}
}
void SavingsAccount::settle(const Date& date) {
double interest = acc.getSum(date) * rate/date.distance(Date(date.getYear()-1,1,1));
if (interest != 0)record(date, interest, "interest");
acc.reset(date, getBalance());
}
CreditAccount::CreditAccount(const Date&date,const string &id,double credit,double rate,double fee):Account(date,id),credit(credit),rate(rate),fee(fee),acc(date,0){}
void CreditAccount::deposit(const Date& date, double amount, const string& desc) {
record(date, amount, desc);
acc.change(date, getDebt());
}
void CreditAccount::withdraw(const Date& date, double amount, const string& desc) {
if (amount - getBalance() > credit) {
error("not enouogh credit");
}
else {
record(date, -amount, desc);
acc.change(date, getDebt());
}
}
void CreditAccount::settle(const Date& date) {
double interest = acc.getSum(date) * rate;
if (interest != 0) record(date, interest, "interest");
if (date.getMonth() == 1)record(date, -fee, "annual fee");
acc.reset(date, getDebt());
}
void CreditAccount::show()const {
Account::show();
cout << "\tAvailable credit:" << getAvailableCredit();
}
运行结果：
