HDU - 1004 Let the Balloon Rise（map）

HDU - 1004 Let the Balloon Rise

#include<iostream>
#include<map> 
using namespace std;
map<string,int>a; 
int main()
{
	int n;string s1,s2;
	while(cin>>n&&n)
	{
		a.clear();
		int maxn=-1;
		while(n--)
		{
			cin>>s1;
			a[s1]++;
			if(a[s1]>maxn)
			{
				maxn=a[s1];
				s2=s1;
			}
		} 
		cout<<s2<<endl;
	}
	return 0;
}