#include <iostream>

using namespace std;

int main()
{
    char buf[10] = { 0 };
    double num1, num2, tmp;
    int code;
    while(1)
    {
        system("cls");
        cout << "输入1我将为你计算两个数相加\n";
        cout << "输入2我将为你计算两个数相减\n";
        cout << "输入3我将为你计算两个数相乘\n";
        cout << "输入4我将为你计算两个数相除\n";
        cout << "输入其他本系统退出\n";
        cin >> tmp;
        code = tmp;
        if (code > 0 && code < 5)
        {
            cout << "请输入第一个数\n";
            cin >> num1;
            cout << "请输入第二个数\n";
            cin >> num2;
        }
        switch (code)
        {
        case 1:
            printf_s("%g+%g=%g\n", num1, num2, num1 + num2);
            break;
        case 2:
            printf_s("%g-%g=%g\n", num1, num2, num1 - num2);
            break;
        case 3:
            printf_s("%g*%g=%g\n", num1, num2, num1 * num2);
            break;
        case 4:
            printf_s("%g/%g=%g\n", num1, num2, num1 / num2);
            break;
        default:
            return 0;
            break;
        }
        cout << "按1键继续,否则退出程序\n";
        cin >> code;
        if (code != 1)
        {
            return 0;
        }
    }
}