169. Majority Element

Majority Element - LeetCode

1. 해시맵 스타일(Dict, Counter 사용)

from collections import Counter

class Solution:
    def majorityElement(self, nums: List[int]) -> int:
        counter = Counter()
        for num in nums:
            counter[num] += 1
        return counter.most_common(1)[0][0]

 

2. 정렬 후 중앙값 반환

class Solution:
    def majorityElement(self, nums: List[int]) -> int:
        return sorted(nums)[len(nums) // 2]

3. Boyer-Moore Voting Algorithm

class Solution:
    def majorityElement(self, nums: List[int]) -> int:
        target, count = 0, 0
        for num in nums:
            if count == 0:
                target = num
            count += 1 if num == target else -1
        return target

 

굉장히 유익한 문제였다.