期中考试补完计划

第一题

#include<iostream>
#include<cstdlib>
#include<ctime>
using namespace std;
class Dice {
public:
    Dice(int n) :sides(n) {};
    int cast();
private:int sides;
};

int Dice::cast() {         
    return(rand() % (sides - 1 + 1) + 1);
}

int main() {
    srand(time(NULL));
    int n, m; 
    cout << "请输入班级人数和你的学号：";
    cin >> n >> m;
    Dice A(n);
    int num = 0;
    for (int i = 0; i<500; i++) {
        if (A.cast() == m)
            num++;
    }
    double p = 0;
    p = num / 500.0;
    cout << "你的学号被抽中的概率为：" << p << endl;
    return 0;
}

第二题

//user.h
#pragma once
#include<iostream>
#include<string>
using namespace std;
class user{
public:
    user(string s1);
    user(string s1, string s2);
    user(user &p);
    void show1();
    static void show2();
    void changepassword();
private:
    int id; 
    string name,password; 
    static int CurrentID;
};

//user.cpp
#include "user.h"
#include<iostream>
#include<string>
using namespace std;
int user::CurrentID = 999;
user::user(string s1):name(s1) {
    password = "111111";
    CurrentID++;
    id = CurrentID;
}

user::user(string s1, string s2) :name(s1), password(s2) {
    CurrentID++;
    id = CurrentID;
}

user::user(user &p) : name(p.name), password(p.password) {
    CurrentID++;
    id = CurrentID;
}

void user::show1() {
    cout << "id：" << id <<  "用户名：" << name <<  "密码：" << password << endl;
}

void user::show2() {
    cout << "CurrentID:" << CurrentID << endl;
}

void user::changepassword() {                //改密码
    int n = 3;
    while (n--) {
        string re;
        cout << "请输入密码：" << endl;
        cin >> re;
        if (password == re) {
            cout << "请输入新密码：" << endl;
            cin >> password;
            break;
        }
        else {
            cout << "密码错误，您还有" << n << "次输入机会。" << endl;
        }
        if (n == 0)
            cout << "密码错误次数过多，请稍后再试！" << endl;
    }
}

//main.cpp
#include"user.h"
#include<iostream>
#include<string>
using namespace std;
int main() {
    user u1("user1");
    user u2("user2", "123456");
    user u3("user3", "666999");
    u1.show1(); u2.show1(); u3.show1(); user u(u3); u3.show2();
    cout << "user2改密码" << endl;
    u2.changepassword();
    u2.show1();
    cout << "user3改密码" << endl;
    u3.changepassword();
    return 0;
}

 

//book.h
#pragma once
#ifndef BOOK_H
#define BOOK_H

#include <string>
using std::string;

class Book {
public:
    Book(string isbnX, string titleX, float priceX);  //构造函数  
    void print(); // 打印图书信息 
private:
    string isbn;
    string title;
    float price;
};
#endif

//book.cpp
#include "book.h"
#include <iostream> 
#include <string>
using namespace std;

Book::Book(string isbnX, string titleX, float priceX) :isbn(isbnX), title(titleX), price(priceX) {    // 构造函数

}

void Book::print() {            // 打印图书信息
    cout << "出版编号:" << isbn << endl;
    cout << "书名:" << title << endl;
    cout << "价格:" << price << endl;
}

//main.cpp
#include "book.h"
#include <vector>
#include <iostream>
using namespace std;

int main()
{
    vector<Book>A;// 定义一个vector<Book>类对象
    string isbn, title;
    float price;
    while (1) {               // 录入图书信息，构造图书对象，并添加到前面定义的vector<Book>类对象中
        cout << "请输入图书信息，若想终止输入, 请输入Quit " << endl;
        cout << "出版编号:" ;
        cin >> isbn ;
        if (isbn != "Quit") {      //判断是否输入
            cout << "书名:";
            cin >> title;
            cout << "价格:";
            cin >> price;
        }
        if (isbn == "Quit")        //输入Quit终止
            break;
        Book a(isbn, title, price);
        A.push_back(a);
    }
    cout << endl;
    for (int i = 0; i<A.size(); i++)  // 输出入库所有图书信息 
        A[i].print();

    return 0;
}