content: package LeetCode.Easy.ContainsDuplicate_II;
  
  import java.util.HashMap;
  
  /*
    219. Contains Duplicate II
  
    Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the absolute difference between i and j is at most k.
  
    Example 1:
    Input: nums = [1,2,3,1], k = 3
    Output: true
  
    Example 2:
    Input: nums = [1,0,1,1], k = 1
    Output: true
  
    Example 3:
    Input: nums = [1,2,3,1,2,3], k = 2
    Output: false
  */
  
  public class Solution {
    public boolean containsNearbyDuplicate(int[] nums, int k) {
      if (nums.length <= 1) return false;
  
      /**
       * * Hashmap approach
       * * TC: O(n), SC: O(n)
       */
      HashMap<Integer, Integer> visited = new HashMap<>();
  
      for (int i = 0; i < nums.length; i++) {
        if (visited.containsKey(nums[i]) && Math.abs(i - visited.get(nums[i])) <= k) return true;
  
        visited.put(nums[i], i);
      }
  
      return false;
    }
  
    public static void main(String[] args) {
      Solution solution = new Solution();
  
      // should be true
      System.out.println(solution.containsNearbyDuplicate(new int[] {1, 2, 3, 1}, 3));
  
      // should be true
      System.out.println(solution.containsNearbyDuplicate(new int[] {1, 0, 1, 1}, 1));
  
      // should be false
      System.out.println(solution.containsNearbyDuplicate(new int[] {1, 2, 3, 1, 2, 3}, 2));
    }
  }
  