随机生成三十个二年级的加减乘除法的题目代码

#include<iostream>
#include<stdlib.h>
#include"time.h"
using namespace std;
void main()
{
    int a, b, i, j, k;
    for (i = 0; i < 30; i++)
    {
        a = rand() % 10;
        b = rand() % 10;
        if (a < b)
        {
            k = a;
            a = b;
            b = k;
        }
        cout << a;
        j = rand() % 4;
        switch (j)
        {
        case 0:cout << '+'; break;
        case 1:cout << '- '; break;
        case 2:cout << '*'; break;
        case 3:cout << '/'; break;

        }

        if (j % 4 == 3)
            b++;
        cout << b << "=" << endl;
    }
}