219. Contains Duplicate II

Topic:

Given an array of integers and a integer K, find out whether there is II distinct indices i and J in the array such that nums[i] = Nums[j] and the difference between I and Jare at most K.

Links: http://leetcode.com/problems/contains-duplicate-ii/

Exercises

Use HashMap to save (nums[i],i) pair, if there is the same key and I-map.get (key) <= K, returns True. Otherwise, returns false after the traversal is complete.

Time Complexity-o (n), Space complexity-o (n)

 Public classSolution { Public BooleanContainsnearbyduplicate (int[] Nums,intk) {if(Nums = =NULL|| Nums.length = = 0)            return false; Map<integer, integer> map =NewHashmap<>();  for(inti = 0; i < nums.length; i++) {            if(Map.containskey (Nums[i])) {if(I-map.get (nums[i]) <=k)return true;        } map.put (Nums[i], i); }                return false; }}

Reference:

219. Contains Duplicate II