1

#include <stdio.h>
#include <time.h>
#include <stdlib.h>
void main()
{
 int a,b,c,d;
 int total1=0,total2=0;
 while(1)
 { 
  srand(time(NULL)); 
 d=a=rand()%100;    b=(rand()%a+a)%10; 
 if(a%4==1&&a<b)c=a,a=b,b=c;  
 if(b==0&&a%4==3)b=rand()%10+1;  
 if(a%4==3&&a%b!=0)  
 {  
  srand(time(0)); 
  a=b*(rand()%a); 
 }
  switch(d%4) 

  { 
  case 0:printf("%d ＋ %d = ",a,b);break;
  case 1:printf("%d － %d = ",a,b);break;
  case 2:printf("%d × %d = ",a,b);break;
  case 3:printf("%d ÷ %d = ",a,b);break;
  }  scanf("%d",&c);  switch(d%4) 
  {  case 0:if(c==a+b){printf("正确 ");
  total1++;}

else {printf("错误 ");total2++;}break; 
  case 1:if(c==a-b){printf("正确 ");total1++;}
   else {printf("错误 ");total2++;}break;
  case 2:if(c==a*b){printf("正确 ");total1++;}
   else {printf("错误 ");total2++;}break; 
  case 3:if(c==a/b){printf("正确 ");total1++;}
   else {printf("错误 ");total2++;}break; 
 } 
  printf("按任意键继续，Q退出！ "); 
  fflush(stdin);  if(getchar()=='Q')break;
 }
 printf("你答对了%d道题，答错%d道题 ",total1,total2);}