leetcode[169]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.

class Solution {
public:
    int majorityElement(vector<int> &num) {
        int n=num.size();
        int res=0;
        int times=0;
        for(int i=0;i<n;i++)
        {
            if(times==0)
            {
                res=num[i];
                times++;
            }
            else
            {
                if(res==num[i])times++;
                else times--;
            }
        }
        return res;
    }
/**
    int majorityElement(vector<int> &num) {
        int n=num.size();
        sort(num.begin(),num.end());
        return num[n/2];
    }

    int majorityElement(vector<int> &num) {
        int n=num.size();
        map<int,int> nmap;
        for(int i=0;i<n;i++)
        {
            nmap[num[i]]++;
            if(nmap[num[i]]>n/2)return num[i];
        }
    }
*/
};