GoogleInterviewCodingChallenge9.java

import java.util.HashSet;
import java.util.Set;

public class GoogleInterviewCodingChallenge9 {
    public static void main(String[] args) {
        /*

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

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

        Example 1:
        Input: [1,2,3,1]
        Output: true

        Example 2:
        Input: [1,2,3,4]
        Output: false

        Example 3:
        Input: [1,1,1,3,3,4,3,2,4,2]
        Output: true

         */

        int[] arr = {1,2,3,1};
        System.out.println(ContainsDuplicate(arr));
        int[] arr2 = {1,2,3,4};
        System.out.println(ContainsDuplicate(arr2));
        int[] arr3 = {1,1,1,3,3,4,3,2,4,2};
        System.out.println(ContainsDuplicate(arr3));

    }

    static boolean ContainsDuplicate(int[] nums){
        Set<Integer> set = new HashSet<>();
        for(int i =0 ; i<nums.length; i++){
            if(set.contains(nums[i])) return true;
            set.add(nums[i]);

        }
        return false;
    }
}