随机产生30个两位数的四则运算（包括真分数的计算）

//3.3.2016 tangyeye
#include<stdio.h>
#include<iostream>
#include<time.h>
using namespace std;
#define MAX 100

int main(int argc,char*argv[])
{   
    int a,b,c,d,e;
    
srand((unsigned)time(NULL));
for(int i=0;i<30;i++)
   {
    a=rand()%MAX;
    b=rand()%MAX;
    d=rand()%MAX;
    e=rand()%MAX;
    
    c=rand()%12+1;

    if(d<e&&e!=0)
    {
    switch(c)
       {
        case 1: cout<<a<<"+"<<b<<endl;
        break;

        case 2: cout<<a<<"-"<<b<<endl;
        break;

        case 3: cout<<a<<"*"<<b<<endl;
        break;

        case 4: cout<<a<<"/"<<b<<endl;
        break;

        case 5: cout<<d<<"/"<<e<<"+"<<b<<endl;
        break;

        case 6: cout<<a<<"+"<<d<<"/"<<e<<endl;
        break;
        
        case 7: cout<<d<<"/"<<e<<"-"<<b<<endl;
        break;

        case 8: cout<<a<<"-"<<d<<"/"<<e<<endl;
        break;

        case 9: cout<<d<<"/"<<e<<" "<<"*"<<b<<endl;
        break;

        case 10: cout<<a<<"*"<<" "<<d<<"/"<<e<<endl;
        break;

        case 11: cout<<d<<"/"<<e<<" "<<"/"<<b<<endl;
        break;

        case 12: cout<<a<<"/"<<" "<<d<<"/"<<e<<endl;
        break;

       }
    
    }
    else
        
        switch(c)
       {
        case 1: cout<<a<<"+"<<b<<endl;
        break;

        case 2: cout<<a<<"-"<<b<<endl;
        break;

        case 3: cout<<a<<"*"<<b<<endl;
        break;

        case 4: cout<<a<<"/"<<b<<endl;
        break;

        case 5: cout<<e<<"/"<<d<<"+"<<b<<endl;
        break;

        case 6: cout<<a<<"+"<<e<<"/"<<d<<endl;
        break;
        
        case 7: cout<<e<<"/"<<d<<"-"<<b<<endl;
        break;

        case 8: cout<<a<<"-"<<e<<"/"<<d<<endl;
        break;

        case 9: cout<<e<<"/"<<d<<" "<<"*"<<b<<endl;
        break;

        case 10: cout<<a<<"*"<<" "<<e<<"/"<<d<<endl;
        break;

        case 11: cout<<e<<"/"<<d<<" "<<"/"<<b<<endl;
        break;

        case 12: cout<<a<<"/"<<" "<<e<<"/"<<d<<endl;
        break;

        }
   
}
 return 0;

}