c++编程 类的练习题以及答案

以下是一些C++编程练习题及其答案：

1. 编写一个程序，要求用户输入两个整数，然后输出它们的和、差、积和商。

#include<iostream>
using namespace std;

int main() {
    int num1, num2;
    cout << "Please enter two integers: ";
    cin >> num1 >> num2;

    cout << num1 << " + " << num2 << " = " << num1 + num2 << endl;
    cout << num1 << " - " << num2 << " = " << num1 - num2 << endl;
    cout << num1 << " * " << num2 << " = " << num1 * num2 << endl;
    cout << num1 << " / " << num2 << " = " << num1 / num2 << endl;

    return 0;
}

2. 编写一个程序，要求用户输入以兆位每秒（Mb/s）为单位的下载速度和文件大小，然后计算并输出下载该文件所需的时间。

#include<iostream>
using namespace std;

int main() {
    double downloadSpeed, fileSize;
    cout << "Please enter the download speed (in Mb/s): ";
    cin >> downloadSpeed;
    cout << "Please enter the file size (in MB): ";
    cin >> fileSize;

    double downloadTime = fileSize * 8 / downloadSpeed;
    cout << "The download time is " << downloadTime << " seconds." << endl;

    return 0;
}

3. 编写一个程序，要求用户输入一个整数，然后输出从1到该整数的所有整数的和。

#include<iostream>
using namespace std;

int main() {
    int num, sum = 0;
    cout << "Please enter an integer: ";
    cin >> num;

    for(int i=1; i<=num; i++) {
        sum += i;
    }

    cout << "The sum of the integers from 1 to " << num << " is " << sum << endl;

    return 0;
}

4. 编写一个程序，要求用户输入一个整数n，然后输出n的阶乘。

#include<iostream>
using namespace std;

int main() {
    int num, factorial = 1;
    cout << "Please enter an integer: ";
    cin >> num;

    for(int i=1; i<=num; i++) {
        factorial *= i;
    }

    cout << num << "! = " << factorial << endl;

    return 0;
}

5. 编写一个程序，要求用户输入一个整数n，然后输出从1到n的所有奇数的和和所有偶数的和。

#include<iostream>
using namespace std;

int main() {
    int num, oddSum = 0, evenSum = 0;
    cout << "Please enter an integer: ";
    cin >> num;

    for(int i=1; i<=num; i++) {
        if(i % 2 == 0) {
            evenSum += i;
        } else {
            oddSum += i;
        }
    }

    cout << "The sum of odd integers from 1 to " << num << " is " << oddSum << endl;
    cout << "The sum of even integers from 1 to " << num << " is " << evenSum << endl;

    return 0;
}