[Programmers] Lv1: 두 개 뽑아서 더하기(68644)

문제

- 링크: https://school.programmers.co.kr/learn/courses/30/lessons/68644?language=java

 

풀이

import java.util.HashSet;

class Solution {
    public int[] solution(int[] numbers) {
        HashSet<Integer> set = new HashSet<>();

        for (int i = 0; i < numbers.length - 1; ++i) {
            for (int j = i + 1; j < numbers.length; ++j) {
                set.add(numbers[i] + numbers[j]);
            }
        }
        
        return set.stream().sorted().mapToInt(Integer::intValue).toArray();
    }
}