Day83

알고리즘 코드카타

Number of Unique Subjects Taught by Each Teacher

select teacher_id, count(distinct subject_id) as cnt
from Teacher
group by teacher_id
;

바탕화면 정리

import java.util.ArrayList;
import java.util.List;

class Solution {
    public int[] solution(String[] wallpaper) {
        int[] answer = {0,0,0,0};
        List<Integer> minmax = new ArrayList<>();
        List<Integer> index = new ArrayList<>();

        for (int w = 0; w < wallpaper.length; w++) {
            boolean filled = false;
            char[] chars = wallpaper[w].toCharArray();

            for (int i = 0; i < chars.length; i++) {
                if (chars[i] == '#'){
                    minmax.add(i);
                    filled = true;
                }
            }

            if (filled){
                index.add(w);
            }
        }

        answer[0] = index.stream().min(Integer::compareTo).get();
        answer[1] = minmax.stream().min(Integer::compareTo).get();
        answer[2] = index.stream().max(Integer::compareTo).get() +1;
        answer[3] = minmax.stream().max(Integer::compareTo).get() +1;

        return answer;
    }
}