169. Majority Element

1. 问题描述

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.
Tags: Array Divide and Conquer Bit Manipulation
Similar Problems： (M) Majority Element II

2. 解题思路

• 详见《剑指offer》

3. 代码

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

4. 反思