Leetcode 217/218. Contains Duplicate

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Question1

Solution1

考虑字典

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class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
        dict = {}
        for num in nums:
            if num not in dict:
                dict[num] = 1
            else:
                return True
        return False

Soltion2

更简单的，用set，然后比较和nums的长度

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class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
        seet = set(nums)
        if len(seet) == len(nums):
            return False
        else:
            return True
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class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
		return len(nums) != len(set(nums))

Question2

Solution1

用字典比较，如果遇到重复数，如果差大于k，则更新对应key的值，否则返回True。

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class Solution:
    def containsNearbyDuplicate(self, nums: List[int], k: int) -> bool:
        if len(nums) == len(set(nums)):
            return False
        dicct = {}
        for i in range(len(nums)):
            if nums[i] not in dicct:
                dicct[nums[i]] = i
            else:
                if i - dicct[nums[i]] > k:
                    dicct[nums[i]] = i
                else:
                    return True
        return False