leetcode 169

1. 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.

1、常规快排class Solution {public:    int majorityElement(vector<int>& nums) {        sort(nums.begin(),nums.end());        return nums[nums.size()/2];    }};2、O(n)class Solution {public:    int majorityElement(vector<int>& nums) {        int k=0;        int temp;        for(int i=0;i<nums.size();++i){            if(k==0){                temp=nums[i];                k=1;            }            else if(nums[i]==temp){                k++;            }            else                k--;        }        return temp;    }};