LeetCode--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.

Credits:
Special thanks to @ts for adding this problem and creating all test cases.

class Solution {public:    int majorityElement(vector<int> &num) {int flag = 0;int n=num.size();if(n==0)return -1;int res = num[0];for(int i=1; i<n; i++){if(num[i]==res)flag++;else{if(flag>0)flag--;elseres = num[i];}}return res;    }};