Codility - Lesson 6 Sorting - 1. Distinct

Source Link:
https://codility.com/programmers/lessons/6-sorting/distinct/

Question: 
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:
A[0] = 2 A[1] = 1 A[2] = 1 A[3] = 2 A[4] = 3 A[5] = 1 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.

My Solution:
Notes:
1. Remember to import (for using "Arrays.sort(xxx[])")
import java.util.*;
2. Using "Arrays.sort(A)" (important)
Arrays.sort(A);
3. for counting the distinct numbers
for(int i=1; i < A.length; i++){
if(A[i] != A[i-1]){ // distinct
result++; 
}
}