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;

}