C++ 计算器实现加减乘除

#include<iostream>
#include<cstring>
using namespace std;
int main()
{
    int a,b;
    while(1){
        int f1=0,f2=0, ans=0;
        char a[99]; cin>>f1>>a;
        int len = strlen(a);
        char *p = a;
        for(int i=1; i<len; i++)
        {
            f2 = f2*10+(p[i]-'0');
        }
        switch(*p){
            case '*': ans = f1*f2; break;
            case '/': ans = f1/f2; break;
            case '+': ans = f1+f2; break;
            case '-': ans = f1-f2; break;
        }
        delete p;
        cout<<ans<<endl;
    }
    return 0;
}