Contains Duplicate II

CodingPhone, OnsiteSoftware EngineerReported Mar, 2026

Examples

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

Discussion

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.

1 <= nums.length <= 10^5

-10^9 <= nums[i] <= 10^9

0 <= k <= 10^5