20150324 练习1 四则运算题目的程序 升级版

#include<stdio.h>
#include<stdlib.h>
main()
{int a,b,op,os;
 printf(" [每课一练 妈妈再也不用担心我的学习]\n");
aq1: printf("选择您想挑战的运算法则\n");/*新版本跟新如下*/
 printf("0.退出 1.加法 2.减法 3.乘法 4.除法 5.做分数题\n");/*添加退出功能*//*增加分数计算*//*增加随机数范围0~100*/
 scanf("%d",&op);
 if(op==0)
     exit;
 switch(op)
 {
aq: case 1:
 a=rand()%100;b=rand()%100;
 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;b=rand()%100;
 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;b=rand()%100;
 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;
 break;
aq3: case 4:
 a=rand()%100;b=rand()%100;
 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;
 aq5: case 5:
 a=rand()%100;b=rand()%100;
 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 aq5;
 }
}