开始刷leetcode day63:Contains Duplicate II

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

Java:

public class Solution {

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

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

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

{

if(hashmap.containsKey(nums[i]))

{

if(i-hashmap.get(nums[i]) <= k) return true;

else hashmap.put(nums[i],i); //replace the old j value

}else

{

hashmap.put(nums[i],i);

}

}

return false;

}

}