package com.leetcode.array;

import java.util.HashSet;

import java.util.Set;

/**

* Created by charles on 12/17/16.

* Given an array of integers, find if the array contains any duplicates.

* Your function should return true if any value appears at least twice in the array, and it should return false if every element is distinct.

*/

public class ContainsDuplicate_217 {

private Set<Integer> set = new HashSet<>();

public boolean containsDuplicate(int[] nums) {

if (nums == null || nums.length == 0) {

return false;

}

int len = nums.length;

for (int i = 0; i < len; i++) {

if (!set.add(nums[i])) {

return true;

}

}

return false;

}

public static void main(String[] args) {

ContainsDuplicate_217 c = new ContainsDuplicate_217();

int[] nums = {1,2,3,1};

System.out.println(c.containsDuplicate(nums));

}

}