51.从键盘上输入任意两个数和一个运算符（+、-、*、/），根据输入的运算符对两个数计算，并输出结果

#include<iostream>
using namespace std;
 
int main()
{
    int x,y;
    char a;
    cout<<"please input two numbers: "<<endl;
    cin>>x>>y;
    cout<<"please input an operational character:"<<endl;
    cin>>a;
 
    switch(a)//switch函数的参数还可用字符
    {
        case '+': cout<<"x+y="<<x+y;break;
        case '-': cout<<"x-y="<<x-y;break;
        case '*': cout<<"x*y="<<x*y;break;
        case '/': cout<<"x/y="<<x/y;break;
        default : break;
    }
 
    return 0;
}