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.

 数组中出现次数超过一半的数字

C++(19ms):

class Solution {
public:
    int majorityElement(vector<int>& nums) {
        int len = nums.size() ;
        int res = nums[0] ;
        int times = 1 ;
        for (int i = 1 ; i < len ; i++){
            if (times == 0){
                res = nums[i] ;
                times = 1 ;
            }else if (res == nums[i]){
                times++ ;
            }else{
                times-- ;
            }
        }
        times = 0 ;
        for(int i = 0 ; i < len ; i++){
            if (res == nums[i])
                times++ ;
        }
        if (times*2 <= len)
            res = 0 ;
        return res ;
    }
};