LeetCode Majority Element

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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.

思路分析：求主元素的经典算法是Moore投票算法，基本可以理解为将主元素和不同元素一一对应相消，最后剩下来的元素就是主元素。具体做法是，初始计数器times和candidate都是0,然后遍历数组，当times为0时置换新的candidate，遇到和candidate相同元素times++，遇到和candidate相异元素times--，如此操作，如果主元素存在，最后剩下的一定是主元素。时间复杂度O（n）,空间复杂度O（1）.

AC Code

public class Solution {    public int majorityElement(int[] nums) {        //0627        //Moore Voting         int n = nums.length;                int candidate = 0;        int times = 0;        for(int i = 0; i < n; i++){            if(times == 0) candidate = nums[i];            if(nums[i] != candidate){                times--;            } else{                times++;            }        }        return candidate;        //0631    }}

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