219. 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.
related links : 217 Contains Duplicate
public class Solution {
public boolean containsNearbyDuplicate(int[] nums, int k) {
Map<Integer,Integer> map = new HashMap<>();
for(int i=0;i< nums.length; i++){
int val = nums[i];
if(map.containsKey(val)){
if(i - map.get(val) <= k) return true;
}
map.put(val, i);
}
return false;
}
}