LeetCode/com/zerroi/leetcode/Three20/ContainsNearbyDuplicate.java

package com.zerroi.leetcode.Three20;

import java.util.HashMap;
import java.util.Map;

public class ContainsNearbyDuplicate {
    public static void main(String[] args) {
        SolutionSecond solutionSecond = new SolutionSecond();
        boolean res = solutionSecond.containsNearbyDuplicate(new int[]{1,2,3,1}, 3);
        System.out.println("res = " + res);
    }
}

class SolutionSecond {
    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])) {
                if (Math.abs(map.get(nums[i]) - i) <= k) {
                    return true;
                }
            }
            map.put(nums[i], i);
        }
        return false;
    }
}