Given an array of integers and an integer k, return true if and only if 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.
public class Solution { public boolean containsNearbyDuplicate(int[] nums, int k) { Map<Integer,Integer> map = new HashMap<>(); for(int i=0;i<nums.length;i++) { if(map.containsKey(nums[i])&&(i-map.get(nums[i]))<=k) return true; else map.put(nums[i],i); } return false; } }
原文：http://www.cnblogs.com/mrpod2g/p/4538601.html