#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<time.h>
int moshi;
int count;
void plus(int first,int second)
{
int result;
printf("%d + %d =",first,second);
scanf("%d",&result);
if(result == first+second)
{
printf("Right!\n");
}
else
{
printf("wrong!\nThe correct answer is:%d\n",first+second);
}
}
void minus(int first,int second)
{
int result;
printf("%d - %d =",first,second);
scanf("%d",&result);
if(result == first-second)
{
printf("Right!\n");
}
else
{
printf("wrong!\nThe correct answer is:%d\n",first+second);
}}
void multiply(int first,int second)
{
int result; //运算结果
printf("%d * %d =",first,second);
scanf("%d",&result);
if(result == first*second)
{
printf("Right!\n");
}
else
{
printf("wrong!\nThe correct answer is:%d\n",first*second);
}
}
void divide(int first,int second)
{
float result; //运算结果
float temp;
second = rand()%100;
printf("%d / %d =",first,second);
if(second==0)
{
printf("Error!\n");
return;
}
scanf("%f",&result);
temp=result*100 - ((float)first/(float)second)*100;
if(abs(temp)<0.01)
{
printf("Right!\n");
}
else
{
printf("wrong!\nThe correct answer is:%f\n",(float)first/(float)second);
}
}
int main()
{
printf("小提示:\n每种模式默认运行5次就得重新选择,中途退出直接按Ctrl+c!\n");
p: printf("请选择模式:\n\n");
printf("----------1:练习模式\n");
printf("----------2:计算模式\n");
count=0;
scanf("%d",&moshi);
switch(moshi)
{
case 1:
{ int n;
int first,second;//保存两个运算的数字
while(true)
{
n=first%4; //除以4取余数，随机确定调用函数
srand(time(NULL));
first = rand()%100;
second = rand()%100;
if(count==5)
goto p;
switch(n)
{
case 0:
{
plus(first,second);
count++;
break;
}
case 1:
{
minus(first,second);
count++;
break;
}
case 2:
{
multiply(first,second);
count++;
break;
}
case 3:
{
divide(first,second);
count++;
break;
}
default:
{
count++;
break;
}
}//switch
}//while
}//case1
case 2:
{
int first,second;
char c,c1; //保存运算符
while(true)
{
scanf("%d%c%d%c",&first,&c,&second,&c1);
if(count==5)
goto p;
switch(c)
{
case ‘+‘:
{
printf("%d+%d=%d\n",first,second,first+second);
count++;
break;
}
case ‘-‘:
{
printf("%d-%d=%d\n",first,second,first-second);
count++;
break;
}
case ‘*‘:
{
printf("%d*%d=%d\n",first,second,first*second);
count++;
break;
}
case ‘/‘:
{
printf("%d/%d=%f\n",first,second,(float)first/(float)second);
count++;
break;
}
default:
{
count++;
break;
}
}//switch
}//while
}//case2
default:
{
break;
}
}
return 0;
}

作业 P17 第一题