Leetcode - Contains Duplicate II Solution

Given an integer array nums and an integer k, return true if there are two distinct indices i and j in the array such that nums[i] == nums[j] and abs(i - j) <= k.

Example 1:

Input: nums = [1,2,3,1], k = 3
Output: true

Example 2:

Input: nums = [1,0,1,1], k = 1
Output: true

Example 3:

Input: nums = [1,2,3,1,2,3], k = 2
Output: false

Constraints:

• 1 <= nums.length <= 105
• -109 <= nums[i] <= 109
• 0 <= k <= 105

Solution in python

class Solution:
    def containsNearbyDuplicate(self, nums: List[int], k: int) -> bool:
        seen = {}
        for index,val in enumerate(nums):
            if seen.get(val,-1)!=-1 and index-seen[val] <= k:
                return True
            else:
                seen[val] = index
        return False