LeetCode:Majority Element Ⅱ

Given an integer array of size n, find all elements that appear more than ⌊ n/3 ⌋ times. The algorithm should run in linear time and in O(1) space.

解法一：

class Solution {
public:
    vector<int> majorityElement(vector<int>& nums) {
        unordered_map<int,int> mapping;
        unordered_map<int,bool> flag;
        vector<int> result;
        int minct=nums.size()/3;
        
        for(int i=0;i<nums.size();i++)
        {
            mapping[nums[i]]++;
        }
         
        for(int i=0;i<nums.size();i++)
        {
            if(mapping[nums[i]]>minct)
                {   
                    if(mapping[nums[i]])
                    {
                    result.push_back(nums[i]);
                    mapping[nums[i]]=false;
                    }
                }
        }
        return result;
        
    }
};