LeetCode 169. Majority Element

Description

https://leetcode.com/problems/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.

Example 1:

Input: [3,2,3]
Output: 3

Example 2:

Input: [2,2,1,1,1,2,2]
Output: 2

Explanation

use a hashmap

Python Solution

class Solution:
    def majorityElement(self, nums: List[int]) -> int:
        counter = {}
        
        for num in nums:
            counter[num] = counter.get(num, 0) + 1
        
        return max(counter.keys(), key=counter.get)

• Time complexity: ~N
• Space complexity: ~N