程序代码：

#include <iostream>
#include <string>
using namespace std;

int main(void)
{
    string friend_name = "JinMaoShiWang";
    char friend_sex = 0;

    while (1)
    {
        cout << "If your friend is a male please enter a 'm' \n"\
            "else please enter a 'f'.\n";
        cin >> friend_sex;
        switch (friend_sex)
        {
        case 'm': cout << "If you see " << friend_name << " please ask him to call me.\n";
            break;
        case 'f': cout << "If you see " << friend_name << " please ask her to call me.\n";
            break;
        default: cout << "You sure your friend is a RENYAO?\n";
        }
        cout << endl;
    }

    return 0;
}