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