//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 absolute difference between i and j is at most k.

class ContainsDuplicatesII {

public boolean containsNearbyDuplicate(int[] nums, int k) {

HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();

for(int i = 0; i < nums.length; i++) {

int current = nums[i];

if(map.containsKey(current) && i - map.get(current) <= k) {

return true;

} else {

map.put(current, i);

}

}

return false;

}

}