n의 배수 고르기

내 풀이

class Solution {
    public int[] solution(int n, int[] numlist) {
        int num = 0;
        for (int j =0; j<= numlist.length-1; j++){
            if(numlist[j] % n == 0) {
                num++;
            }
        }
        int k = 0;    
        int[] answer = new int[num];
        for(int i =0; i<= numlist.length-1; i++) {
            if(numlist[i] % n == 0) {
                answer[k] = numlist[i];
                k++;
            }
        }
        return answer;
    }
}

간단한 풀이 (Arrays 이용)

class Solution {
    public int[] solution(int n, int[] numList) {
        return Arrays.stream(numList).filter(value -> value % n == 0).toArray();
    }
}

ArrayList 이용한 방법

import java.util.ArrayList;
class Solution {
    public int[] solution(int n, int[] numlist) {


        ArrayList<Integer> List = new ArrayList<>();
        for(int i = 0;i < numlist.length; i++){
            if(numlist[i] % n == 0){
                List.add(numlist[i]);}}
            int[] answer = new int[List.size()];
            for(int i = 0; i< List.size(); i++){
                answer[i] = List.get(i);
                }
        return answer;
    }
}