LeetCode219 哈希表，人麻了

[荼蘼糯]

class Solution:
    def containsNearbyDuplicate(self, nums: List[int], k: int) -> bool:
        pos = {}
        for value, i in enumerate(nums):
            if i in pos and value - pos[i] <= k:
                return True
            pos[i] = value
        return False