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.

注意此题中要求的数一定要超过半数

class Solution {
public:
    int majorityElement(vector<int>& nums) {
        int count =0;
        int num = 0;
        for(auto n:nums){
            if(n == num)
                count++;
            else if(count == 0)
                num = n;
            else
                count--;
        }
        return num;
    }
};

int majorityElement(vector<int>& nums) {
        int count =0;
        int num = 0;
        for(auto n:nums){
            if(count == 0){
                num = n;
                count = 1;
            }else if(n == num)
                count++;
            else
                count--;
        }
        return num;
}