第二次作业 随机数四则运算

源代码如下所示：

#include<iostream.h>
      #include<stdlib.h>
      #include<time.h>
      int main()
      {
      int a,b,c,t;
      srand(time(NULL));
      for(int i=0;i<30;i++)
      {
      a=rand()%100;
      b=rand()%100;
      c=rand()%4;
      switch(c)
      {
      case 0:
      cout<<a<<"+"<<b<<"="<<endl;
      break;
      case 1:
      if(a<b)
      {
      t=a;
      a=b;
      b=t;
      }
      cout<<a<<"-"<<b<<"="<<endl;
      break;
      case 2:
      cout<<a<<"*"<<b<<"="<<endl;
      break;
      case 3:
      if(b!=0)
      {
      cout<<a<<"/"<<b<<"="<<endl;
      }
      else
      {
      i=i-1;
      }
      break;
      }
      }
      cout<<"30道数学测试题结束"<<endl;
      return 0;
      }

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