C语言编程一个四则运算练习系统;本系统要求能随机产生加，减，乘，除混合运算练习题，练习者给出答案后，

Question

统判定答案是否正确，并给出相应的提示。

这是课设需要，需限时编出，跪求各位大侠啦

Answer 1

#include<stdio.h>
#include<time.h>
#include<stdlib.h>

int i;

void main()
{
char s;
double deshu,daan;
srand(time(0));
int a=rand()%1000+1;
int b=rand()%1000+1;
int c=rand()%4+1;
switch(c)
{
case 1: s='+';break;
case 2: s='-';break;
case 3: s='*';break;
case 4: s='/';break;
}
printf("\n%d%c%d= ",a,s,b);
scanf("%lf",&deshu);
if(c==1)
{
daan=a+b;
if(deshu==daan) printf("正确！\n");
else printf("答错了…答案是 %g\n",daan);
}
if(c==2)
{
daan=a-b;
if(deshu==daan) printf("正确！\n");
else printf("答错了…答案是 %g\n",daan);
}
if(c==3)
{
daan=a*b;
if(deshu==daan) printf("正确！\n");
else printf("答错了…答案是 %g\n",daan);
}
if(c==4)
{
daan=a/b;
if(deshu==daan) printf("正确！\n");
else printf("答错了…答案是 %f\n",daan);
}
i++; //题目数加1
if(i==10) exit(0); //一共10道题
else main(); //返回继续执行
}

Answer 2

你试一下，好像不太对劲，除法的……
抱歉，没看见“混合运算”，只有一种...抱歉……
#include<stdio.h>
#include<time.h>
#include<stdlib.h>

int i;

void main()
{
char s;
double deshu,daan;
srand(time(0));
int a=rand()%1000+1;
int b=rand()%1000+1;
int c=rand()%4+1;
switch(c)
{
case 1: s='+';break;
case 2: s='-';break;
case 3: s='*';break;
case 4: s='/';break;
}
printf("\n%d%c%d= ",a,s,b);
scanf("%lf",&deshu);
if(c==1)
{
daan=a+b;
if(deshu==daan) printf("正确！\n");
else printf("答错了…答案是 %g\n",daan);
}
if(c==2)
{
daan=a-b;
if(deshu==daan) printf("正确！\n");
else printf("答错了…答案是 %g\n",daan);
}
if(c==3)
{
daan=a*b;
if(deshu==daan) printf("正确！\n");
else printf("答错了…答案是 %g\n",daan);
}
if(c==4)
{
daan=a/b;
if(deshu==daan) printf("正确！\n");
else printf("答错了…答案是 %f\n",daan);
}
i++; //题目数加1
if(i==10) exit(0); //一共10道题
else main(); //返回继续执行
}