LeetCode 题解（128）: Majority Element

题目：

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.

题解：

给定majority一定存在，所以用网上学来的一次扫描算法, 用一个count和一个current表示当前的majority数，最后的current就是majority。

C++版：

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

Java版：

public class Solution {
    public int majorityElement(int[] nums) {
        int count = 1;
        int current = nums[0];
        for(int i = 1; i < nums.length; i++) {
            if(count == 0) {
                current = nums[i];
                count++;
            } else {
                if(nums[i] == current) {
                    count++;
                } else {
                    count--;
                }
            }
        }
        return current;
    }
}

Python版：

class Solution:
    # @param {integer[]} nums
    # @return {integer}
    def majorityElement(self, nums):
        count = 1
        current = nums[0]
        for i in range(1, len(nums)):
            if count == 0:
                current = nums[i]
                count = 1
            else:
                if current == nums[i]:
                    count += 1
                else:
                    count -= 1
        return current