Codility--- Distinct

Write a function

class Solution { public int solution(int[] A); }

that, given a zero-indexed array A consisting of N integers, returns the number of distinct values in array A.

Assume that:

• N is an integer within the range [0..100,000];
• each element of array A is an integer within the range [−1,000,000..1,000,000].

For example, given array A consisting of six elements such that:

the function should return 3, because there are 3 distinct values appearing in array A, namely 1, 2 and 3.

Complexity:

• expected worst-case time complexity is O(N*log(N));
• expected worst-case space complexity is O(N), beyond input storage (not counting the storage required for input arguments).

Elements of input arrays can be modified.

// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");
import java.util.HashSet;
class Solution {
    public int solution(int[] A) {
        // write your code in Java SE 8
        HashSet hs = new HashSet();
        for(int i=0; i<A.length;i++) {
            hs.add(A[i]);
        }
        return hs.size();
    }
}


https://codility.com/demo/results/trainingB7XB2W-7ZM/