实验1-四则运算

#include<iostream>

using namespace std;

#include<stdlib.h>

#include<time.h>

int main()

{

 int a,b,ans,res,c1=0,c2=0,c3=0,c4=0,t,i,N;

 int p;

 srand((unsigned)time(NULL));

 while(1)

 {

  cout<<"\n--小学生四则运算练习题--\n";

  cout<<"--1.加法运算--\n";

        cout<<"--2.减法运算--\n";

        cout<<"--3.乘法运算--\n";

        cout<<"--4.除法运算--\n";

        cout<<"--5.退出练习--\n";

        cout<<"--请输入数字1-5:--\n";

     cin>>p;

  switch(p)

  {

  case 1:

      cout<<"--请进行加法运算--\n";

      cout<<"--请输入题目个数--\n";

   cin>>N;

      for(i=1;i<=N;i++)

   {

    a=rand()%99+1;// rand()%a的结果最大为a-1*

       b=rand()%99+1;

       res=a+b;

          cout<<a<<"+"<<b<<"=";

          cin>>ans;

        if(ans==res)

    {

    cout<<"你答对了!\n";

    c1++;

    }

       else

    {

      cout<<"你答错了!\n";

      cout<<"正确答案是:"<<res<<endl;

    }

   }

  

   break;

       case 2:

     cout<<"--请进行减法运算--\n";

     cout<<"--请输入题目个数--\n";

     cin>>N;

     for(i=1;i<=N;i++)

     {

      a=rand()%99+1;

      b=rand()%99+1;

      if(a<b)

 

      {

       t=a;a=b;b=t;

      }

        res=a-b;

       cout<<a<<"-"<<b<<"=";

          cin>>ans;

       if(ans==res)

    {

     cout<<"你答对了!\n";

     c2++;

    }

    else

    {

     cout<<"你答错了!"<<endl;

     cout<<"正确答案是:"<<res<<endl;

    }

     }

           

     break;

    case 3:

      cout<<"--请进行乘法运算--\n";

      cout<<"--请输入题目个数--\n";

         cin>>N;

     for(i=1;i<=N;i++)

     {

      a=rand()%99+1;

      b=rand()%99+1;

      res=a*b;

      cout<<a<<"*"<<b<<"=";

      cin>>ans;

      if(ans==res)

      {

       cout<<"你答对了!\n";

       c3++;

      }

      else

    {

     cout<<"你答错了!"<<endl;

     cout<<"正确答案是:"<<res<<endl;

    }

     }

      

     break;

    case 4:

      cout<<"--请进行除法运算--\n";

      cout<<"--请输入题目个数--\n";

      cin>>N;

     for(i=1;i<=N;i++)

     {

      a=rand()%99+1;

      b=rand()%99+1;

      res=a/b;

      cout<<a<<"/"<<b<<"=";

      cin>>ans;

      if(ans==res)

      {

       cout<<"你答对了!\n";

       c4++;

      }

      else

    {

     cout<<"你答错了!"<<endl;

     cout<<"正确答案是:"<<res<<endl;

    }

     }

    

     break;

    case 5:goto END;

       }

 }

END:cout<<"再见!\n";

return 0;

}