#include
using namespace std;
int main()
{
int a,b,sum;
char choice,end;
cout<<"enter a,b:";
cin>>a;
cin>>b;
cout<<"your choice(+,-,*,/):";
cin>>choice;
switch(choice)
{
case '+':
sum=a+b;
//cout<<"加法运算:sum="<
case '-':
if(a>b)
sum=a-b;
else
sum=b-a;
//cout<<"减法运算:sum="<
case '*':
sum=a*b;
//cout<<"乘法运算:sum="<
case '/':
sum=a/b;
//cout<<"除法运算:sum="<
}
cout<<"sum="<
cin>>end;
}