Majority Element

Given an array of size n, find the majority element. The majority element is the element that appears more than ? n/2 ? times.

You may assume that the array is non-empty and the majority element always exist in the array.

#include<iostream>
#include<vector>
#include<algorithm>
#include<map>
using namespace std;
//先排序
int majorityElement(vector<int> &num) {
	sort(num.begin(),num.end());
	int mid = num.size()/2;
	return num[mid];
}
//利用关联容器
int majorityElement(vector<int> &num) {
	if(num.size()==1)
		return num[0];
	map<int,int> Mapcount;
	for (int i =0;i!=num.size();++i)
	{
		if (Mapcount.count(num[i]))
		{
			++Mapcount[num[i]];
			if (Mapcount[num[i]]>num.size()/2)
				return num[i];
		}
		else
			Mapcount.insert(make_pair(num[i],1));
	}
}
//将重复点与非重复点成对计算
int majorityElement(vector<int> &num) {
	int nTimes = 0;
	int candidate = 0;
	for(int i = 0; i < num.size(); i ++){
		if(nTimes == 0){
			candidate = num[i];
			nTimes = 1;
		}
		else{
			if(candidate == num[i])
				nTimes ++;
			else
				nTimes --;
		}
	}
	return candidate;
}

Majority Element

原文：http://blog.csdn.net/li_chihang/article/details/44618033