20160317第二题

#include<stdio.h>
 
#include<stdlib.h>
#include<time.h>
main()
{
int a,b,op,os;
 
printf(" [四则运算来挑战]\n");
aq1:    printf("选择你想挑战的运算法则\n");
printf("1.加法 2.减法 3.乘法 4.除法\n");
scanf("%d",&op);
switch(op)
{
aq: case 1:
srand((unsigned)time(NULL));
a=rand()%100+1;b=rand()%100+1;
printf("题目为：%d + %d = ?\n\n",a,b);
printf("1.查看答案 2.做下一题\n");
scanf("%d",&os);
if(os==1)
{printf("%d + %d =%d\n\n\n",a,b,a+b);
goto aq1;
}
else
goto aq;
break;
at:  case 2:a=rand()%100+1;b=rand()%100+1;
printf("题目为：%d - %d = ?\n\n",a,b);
printf("1.查看答案 2.做下一题\n");
scanf("%d",&os);
if(os==1)
{printf("%d - %d =%d\n\n\n",a,b,a-b);
goto aq1;
}
else
goto at;
break;
aq2:     case 3:
a=rand()%100+1;b=rand()%100+1;
printf("题目为：%d * %d = ?\n\n",a,b);
printf("1.查看答案 2.做下一题\n");
scanf("%d",&os);
if(os==1)
{printf("%d * %d =%d\n\n\n",a,b,a*b);
goto aq1;
}
else
goto aq2;
aq3:     case 4:
a=rand()%100+1;b=rand()%100+1;
printf("题目为：%d / %d = ?\n\n",a,b);
printf("1.查看答案 2.做下一题\n");
scanf("%d",&os);
if(os==1)
{printf("%d / %d =%d\n\n\n",a,b,a/b);
goto aq1;
}
else
goto aq3;
break;
}
}