[프로그래머스] Lv3 문제풀이2(feat. JAVA)

야근 지수

import java.util.*;

class Solution {
    public long solution(int n, int[] works) {
        long answer = 0;
        Arrays.sort(works);
        long[] cnt = new long[works[works.length-1] + 1];

        long sum = 0;
        for(int a : works) {
            sum += a;
            cnt[a]++;
        }

        if(sum <= n) return answer;

        for(int i = cnt.length-1; i > 1; i--) {
            if(cnt[i] < n) {
                cnt[i-1] += cnt[i];
                n -= cnt[i];
                cnt[i] = 0;
            } else {
                cnt[i] -= n;
                cnt[i-1] += n;
                n = 0;
                break;
            }
        }
        if(n!=0)
            cnt[1] -= n;

        for(int i = 1; i < cnt.length; i++) {
            if(cnt[i] == 0) continue;
            answer += i * i * cnt[i];
        }

        return answer;
    }
}

 

 

 

최고의 집합 

import java.util.*;

class Solution {
    public int[] solution(int n, int s) {
        int[] answer = new int[n];
        if(n > s) {
            return new int[] {-1};
        }else if (n == s) {
            Arrays.fill(answer, 1);
        } else {
            Arrays.fill(answer, s / n);
            s = s % n;

            for(int i = n-s; i < n; i++) {
                answer[i]++;
            }
        }
        return answer;
    }
}

 

 

 

단어변환 - DFS/BFS

class Solution {
    public int min = 10;
    public void bfs(String begin, String target, String[] words, int cnt){
        if(cnt > min) return ;
        if(begin.equals(target)) {
            if(cnt < min) {
                min = cnt;
            }
            return ;
        }
        boolean[] visit = new boolean[words.length];
        for(int i = 0; i < words.length; i++) {
            if(visit[i]) continue;

            String word = words[i];
            int c = 0;
            for(int j = 0; j < begin.length(); j++) {
                if(begin.charAt(j) != word.charAt(j)){
                    c++;
                }
                if(c > 1)break;
            }
            if(c == 1) {
                visit = new boolean[words.length];
                visit[i] = true;
                bfs(word, target, words, cnt + 1);
            }
        }
    }

    public int solution(String begin, String target, String[] words) {
        int answer = 0;
        String str = String.join("", words);

        for(char c :  target.toCharArray()) {
            if(!str.contains(String.valueOf(c)))
                return answer;
        }
        bfs(begin, target, words, 0);
        return min;
    }
}