Leetcode Contains Duplicate II

Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the difference between i and j is at most k.

Difficulty: Easy

public class Solution {    public boolean containsNearbyDuplicate(int[] nums, int k) {        if(k == 0)            return false;        HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();        for(int i = 0; i < nums.length; i++){            if(!map.containsKey(nums[i])){                map.put(nums[i], i);            }            else{                          if(Math.abs(map.get(nums[i]) - i) <= k)                    return true;                                map.put(nums[i], i);            }        }        return false;    }}