帮我看看这个代码错在哪

Question

#include<stdio.h>
#include<conio.h>
void main()
{
int m,n,result,flag=0;
/**/char ch,/**/ 
printf("Input an expression:");
scanf("%d%c%d",&m,&ch,&n);
/**/switch ch/**/ 
{
case '+':result=m+n;break;
case '-':result=m-n;break;
case '*':result=m*n;break;
case '%':result=m%n;break;
case '/':result=m/n;break;
default:{printf("Error!\n");flag=1;}
}
if(!flag)printf("%d%c%d=%d\n",m,ch,n,result);
getch();
}

Answer 1

char ch, 分号结束char ch; switch (ch)加括号