Java for LeetCode 219 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 i and j is at most k.

解题思路：

HashMap，JAVA实现如下：

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