四则运算

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

#define N 100//随机出100道题目

void main()
{
int num1, num2, num3, count=0, result,resultTrue,flag; //result:用户输入结果 resultTrue:正确结果 flag:0 先计算左边 1先计算右边
char op1, op2;
srand(time(NULL)); //启动随机数生成器
do {
count++;
num1 = rand() % 100+1;
num2 = rand() % 100+1;
num3 = rand() % 100+1;
switch (num1 % 4)
{
case 0:
op1 = '+';
break;
case 1:
op1 = '-';
break;
case 2:
op1 = '*';
break;
case 3:
op1 = '/';
break;
default:
break;
}
switch (num2 % 4)
{
case 0:
op2 = '+';
flag = 0;
break;
case 1:
op2 = '-';
flag = 0;
break;
case 2:
op2 = '*';
if((op1=='*')||(op1=='/')) flag = 0;
else flag = 1;
break;
case 3:
op2 = '/';
if((op1=='*')||(op1=='/')) flag = 0;
else flag = 1;
break;
default:
break;
}
printf("%d %c %d %c %d = ",num1,op1,num2,op2,num3);
if(flag==0)
{
resultTrue = 0;
switch (op1)
{
case '+':
resultTrue = num1+num2;
break;
case '-':
resultTrue = num1-num2;
break;
case '*':
resultTrue = num1*num2;
break;
case '/':
resultTrue = num1/num2;
break;
default:
break;
}
switch (op2)
{
case '+':
resultTrue += num3;
break;
case '-':
resultTrue -= num3;
break;
case '*':
resultTrue *= num3;
break;
case '/':
resultTrue /= num3;
break;
default:
break;
}
}
else
{
resultTrue = 0;
switch (op2)
{
case '+':
resultTrue = num2+num3;
break;
case '-':
resultTrue = num2-num3;
break;
case '*':
resultTrue = num2*num3;
break;
case '/':
resultTrue = num2/num3;
break;
default:
break;
}
switch (op1)
{
case '+':
resultTrue = num1 + resultTrue;
break;
case '-':
resultTrue = num1 - resultTrue;
break;
case '*':
resultTrue = num1 * resultTrue;
break;
case '/':
resultTrue = num1 / resultTrue;
break;
default:
break;
}
}
scanf("%d",&result);
if (result == resultTrue)
printf("结果正确!\n");
else
printf("结果错误!\n");
}
while(count<=N);
}