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leetcode169寻找出现次数最多的数

admin 11月 13, 2020 0

在一个长度为n的数组中，寻找出现次数大于n/2的数

169. Majority Element

Given an array of size n, find the majority element. The majority element is the element that appears more thann/2times.

You may assume that the array is non-empty and the majority element always exist in the array.

最直接的思路，用一个字典保存所有数出现的次数，当出现大于n/2的直接返回

class (object):
    def majorityElement(self, nums):
        d = dict()
        l = len(nums)
        for i in range(l):
            if(d.has_key(nums[i])):
                d[nums[i]] = d[nums[i]]+1
            else:
                d[nums[i]] = 0
            if(d[nums[i]]>=l/2):
                return nums[i]

看到别人的思路，把数组排序，中间的值一定是出现次数大于等于2的值

class (object):
    def majorityElement(self, nums):
        nums.sort()
        return nums[len(nums)/2]