Leetcode 697. Degree of an Array

文章作者：Tyan
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1. Description

Degree of an Array

2. Solution

• Version 1

from collections import Counter
class Solution:
    def findShortestSubArray(self, nums):
        stat = Counter(nums)
        degree = 0
        result = len(nums)
        for key, value in stat.items():
            if value > degree:
                degree = value

        for key, value in stat.items():
            if value == degree:
                left = 0
                right = len(nums) - 1
                while nums[left] != key or nums[right] != key:
                    if nums[left] != key:
                        left += 1
                    if nums[right] != key:
                        right -= 1
                sub_length = right - left + 1
                if result > sub_length:
                    result = sub_length
        return result

• Version 2

from collections import Counter
class Solution:
    def findShortestSubArray(self, nums):
        stat = Counter(nums)
        degree = 0
        result = len(nums)
        for key, value in stat.items():
            if value > degree:
                degree = value

        for index, value in enumerate(nums):
            if value in stat and stat[value] == degree:
                end = len(nums) - 1
                while nums[end] != value:
                    end -= 1
                sub_length = end - index + 1
                del stat[value]
                if result > sub_length:
                    result = sub_length
        return result

• Version 3

class Solution:
    def findShortestSubArray(self, nums):
        degree = 0
        result = len(nums)
        stat = {}
        for index, value in enumerate(nums):
            if value in stat:
                stat[value]['degree'] += 1
                stat[value]['end'] = index
            else:
                stat[value] = {'degree': 1, 'start': index, 'end': index}

            sub_length = stat[value]['end'] - stat[value]['start'] + 1
            if stat[value]['degree'] > degree:
                degree = stat[value]['degree']
                result = sub_length
            if stat[value]['degree'] == degree and sub_length < result:
                result = sub_length

        return result

• Version 4

class Solution:
    def findShortestSubArray(self, nums):
        degree = 0
        result = len(nums)
        stat = {}
        for index, value in enumerate(nums):
            if value in stat:
                stat[value]['degree'] += 1
            else:
                stat[value] = {'degree': 1, 'start': index}

            sub_length = index - stat[value]['start'] + 1
            if stat[value]['degree'] > degree:
                degree = stat[value]['degree']
                result = sub_length
            elif stat[value]['degree'] == degree and sub_length < result:
                result = sub_length

        return result

Reference

1. https://leetcode.com/problems/degree-of-an-array/