pku2550.cpp

这是ACM 方面的资料 是PKU的 北京大学的出来的

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

typedef map < string, int> WordMap;

int main()
{
	int K, i, cnt;
	string s, ps;
	while (cin>>K)
	{
		WordMap w;
		WordMap::iterator pos;
		while (cin>>s)
		{
			if (s == "EndOfText")
			{
				break;
			}
			ps = "";
			for (i = 0; i <= s.length(); i++)
			{
				if (i != s.length() && isalpha(s[i]))
				{
					ps += (char)tolower(s[i]);
				}
				else
				{
					if (ps != "")
					{
						if (w.find(ps) == w.end())
						{
							w[ps] = 1;
						}
						else
						{
							w[ps]++;
						}
					}
					ps = "";
				}
			}
		}
		for (pos = w.begin(), cnt = 0; pos != w.end(); pos++)
		{
			if (pos->second == K)
			{
				cout<<pos->first<<endl;
				cnt++;
			}
		}
		if (!cnt)
		{
			cout<<"There is no such word. \n";
		}
		cout<<endl;
	}
	return 0;
}