[Leetcode，python] Majority Element 众数

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.

解决方案

class Solution(object):
    def majorityElement(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        num_dict = {}
        for i in nums:
            if i in num_dict:
                num_dict[i] +=1
            else:
                num_dict[i] = 1
        return max(num_dict.items(), key=lambda x: x[1])[0]

思路说明

建立一个字典统计每个元素出现次数，返回值最大的键。