四则运算1（改）

//随机生成30道四则运算题目，要求有整数和真分数
#include<stdio.h>
#include<iostream>
#include<time.h>
using namespace std;

int main()
{
    int i, a, b, c, d, e, f,g;
    srand((unsigned)time(NULL));//时间种子，每次出现随机数不同
    for (i = 0; i < 30;i++)
    {
        
        a = rand() % 100;
        b = rand() % 100;
        e = rand() % 100;
        f = rand() % 100;
        switch (d = rand() % 2)
        {
        case 0:   //整数
        {
                  switch (c = rand() % 4)
                  {
                  case 0:cout << a << "+" << b << "=" << endl; break;
                  case 1:cout << a << "-" << b << "=" << endl; break;
                  case 2:cout << a << "*" << b << "=" << endl; break;
                  case 3:
                  {
                            while (b == 0)
                            {
                                b = rand() % 100;
                            }
                            cout << a << "÷" << b << "=" << endl; break;
                  }
                  }
        }break;
        case 1://真分数
        {
                   while (a==0||b == 0 || a >= b)
                   {
                       a = rand() % 100;
                       b = rand() % 100;
                   }
                   while (e==0||f == 0 || e >= f)
                   {
                       e = rand() % 100;
                       f = rand() % 100;
                   }
                   switch (g = rand() % 4)
                   {
                   case 0: cout << a << "/" << b << "+" << e << "/" << f << "=" << endl; break;
                   case 1: cout << a << "/" << b << "-" << e << "/" << f << "=" << endl; break;
                   case 2: cout << a << "/" << b << "*" << e << "/" << f << "=" << endl; break;
                   case 3: cout << a << "/" << b << "÷"<< e << "/" << f << "=" << endl; break;
                   }
        }break;
        }
    }
}