寻找发帖水王

http://www.cnblogs.com/pangxiaodong/archive/2011/09/24/2189593.html

问题描述：我这里有很多学生的学号（有重复的），已知其中有K个学生，他们的学号出现的次数都超过了总数的1/(K+1)，请把这K个学号找出来。

上代码：

#include<iostream>
#include<list>
#include<utility>

using namespace std;

template<typename T,size_t N>
inline size_t getArrLen(T (&arr)[N]){
    return N;
}

const int K=3;

int main(){
    string IDs[]={"M201070347","M201070360","M201070359","M201070351","M201070358","M201070358","M201070359","M201070360","M201070360","M201070358","M201070359"};
    int len=getArrLen(IDs);
    list<pair<string,int> > words;
    
    for(int i=0;i<len;i++){
		list<pair<string,int> >::iterator pos=words.begin();
		while(pos!=words.end()){
			if(pos->first==IDs[i])
				break;
			pos++;
		}
		if(pos!=words.end()){    //在words中
			pos->second++;
			
		}else{			//不在words中
			if(words.size()<K){		//words中元素还不够K个
				words.push_back(pair<string,int>(IDs[i],1));
			}
			else{			//words中元素已够K个
				list<pair<string,int> >::iterator itr=words.begin();
				while(itr!=words.end()){
					itr->second--;
					itr++;
				}
				itr=words.begin();
				while(itr!=words.end()){
					if(itr->second==0){
						list<pair<string,int> >::iterator itt=itr;
						itr++;
						words.erase(itt);
					}else{
						itr++;
					}
				}
			}
		}
	}
	
	list<pair<string,int> >::iterator itr=words.begin();
	while(itr!=words.end()){
		cout<<itr->first<<"\t";
		itr++;
	}
	cout<<endl;
	
	return 0;
}