c语言的基础题，请帮忙

编写程序要求用户输入12小时制的时间，然后用24小时制显示该时间：
Enter a 12-hou time:9:11PM
Equivalent 24-hour time:21:11

http://blog.csdn.net/qiulh125/article/details/50392381

 #include<iostream>
using namespace std;
int main()
{
    int hours,minute;
    char s[5];
    char c; 
    cout<<"please input:"<<endl;
    //需要在英文模式下输入 
    scanf("%d%c%d%s",&hours,&c,&minute,s);
    if(s=="pm")
    {
     cout<<hours+12<<":"<<minute<<endl;
    }
    else
    {
         cout<<hours+12<<":"<<minute<<endl;
    }
    return 0;
}