프로그래머스(모의고사)

import java.util.*;

class Solution {
    public int[] solution(int[] answers) {
        int[] answer = {};
        int[] first = {1,2,3,4,5};
        int[] second = {1,3,4,5};
        int[] third = {3,1,2,4,5};
        int[] uAnswer = new int[3];
        //1,2,3,4,5,1,2,3,4,5,1,2,3,4,5
        //1는 (answer % 5 == 0) ? 5 : answer % 5;
        //(answer % 2 == 1) ? 2 : (answer / 2) % 4;
        //1,3,4,5,1,3,4,5
        //2,1,2,3,2,4,2,5,2,1,2,3,2,4,2,5
        //33,11,22,44,55
        //
        for(int i = 0; i<answers.length;++i) {
            
            int f = first[i%5];
            int s = (i%2 == 0) ? 2 : second[(i/2)%4];
            int t = third[(i/2)%5];
            if(f == answers[i])
                uAnswer[0]++;
            if(s == answers[i])
                uAnswer[1]++;
            if(t == answers[i])
                uAnswer[2]++;
        }
        int max = -1;
        List<Integer> list = new ArrayList<>();
        for(int i = 0; i<uAnswer.length;++i) {
            if(uAnswer[i] > max)
                max = uAnswer[i];
        }
        for(int i = 0; i<uAnswer.length;++i) {
            if(uAnswer[i] == max)
                list.add(i+1);
        }
        answer = new int[list.size()];
        for(int i = 0; i<list.size();++i)
            answer[i] = list.get(i);
        return answer;
    }
}

찍는 방법의 규칙성만 찾아내면 되는 문제