Atcoder Boot camp Problems Medium 6 ~ 10

 

6. B - Minesweeper

 

코드

import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        StringTokenizer st;

        st = new StringTokenizer(br.readLine());
        int h = Integer.parseInt(st.nextToken());
        int w = Integer.parseInt(st.nextToken());
        String[] strs = new String[h];

        for (int i = 0; i < strs.length; i++) {
            strs[i] = br.readLine();
        }

        int[][] board = new int[h][w];
        for (int y = 0; y < h; y++) {
            for (int x = 0; x < w; x++) {
                if (strs[y].charAt(x) == '#') {
                    board[y][x] = -100;
                    for (int dy = -1; dy <= 1; dy++) {
                        for (int dx = -1; dx <= 1; dx++) {
                            int ny = y + dy;
                            int nx = x + dx;
                            if (ny < 0 || ny >= h || nx < 0 || nx >= w) continue;
                            board[ny][nx]++;
                        }
                    }
                }
            }
        }

        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < board.length; i++) {
            for (int j = 0; j < board[0].length; j++) {
                if (board[i][j] < 0) sb.append('#');
                else sb.append(board[i][j]);
            }
            sb.append('\n');
        }
        bw.write(sb.toString());

        bw.flush();
        bw.close();
        br.close();
    }
}

 

 

7. B - Cut and Count

 

코드

import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        StringTokenizer st;

        int n = Integer.parseInt(br.readLine());
        String str = br.readLine();

        int ans = 0;
        for (int i = 1; i < str.length(); i++) {
            boolean[] a = new boolean[26];
            for (int j = 0; j < i; j++) {
                a[str.charAt(j) - 'a'] = true;
            }

            boolean[] b = new boolean[26];
            for (int j = i; j < str.length(); j++) {
                b[str.charAt(j) - 'a'] = true;
            }

            int cnt = 0;
            for (int j = 0; j < 26; j++) {
                if (a[j] && b[j]) cnt++;
            }
            ans = Math.max(ans, cnt);
        }

        bw.write(ans + "");

        bw.flush();
        bw.close();
        br.close();
    }
}

 

 

8. C - Colorful Leaderboard

 

풀이

 최소를 구할 때 주의해야 한다. rating이 3200 미만인 인원이 한 명이라도 있는 경우 서로 다른 색깔의 수이고 없다면 rating이 3200 이상인 인원들의 색을 하나로 고정한 경우가 최소이다.

 

 

코드

import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        StringTokenizer st;

        int[] score = new int[]{400, 800, 1200, 1600, 2000, 2400, 2800, 3200};
        int n = Integer.parseInt(br.readLine());
        st = new StringTokenizer(br.readLine());

        boolean[] color = new boolean[score.length];
        int free = 0;
        for (int i = 0; i < n; i++) {
            int cur = Integer.parseInt(st.nextToken());
            int idx = 0;

            while (idx < score.length && score[idx] <= cur) idx++;

            if (idx < score.length) color[idx] = true;
            else free++;
        }

        int cnt = 0;
        for (int i = 0; i < color.length; i++) {
            if (color[i]) cnt++;
        }

        int min = Math.max(cnt, 1);
        int max = cnt + free;
        bw.write(min + " " + max);

        bw.flush();
        bw.close();
        br.close();
    }
}

 

 

9. B - Choose Integer

 

코드

import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        StringTokenizer st;

        st = new StringTokenizer(br.readLine());
        int a = Integer.parseInt(st.nextToken());
        int b = Integer.parseInt(st.nextToken());
        int c = Integer.parseInt(st.nextToken());

        HashSet<Integer> set = new HashSet<>();
        int sum = a;
        while (!set.contains(sum % b)) {
            set.add(sum % b);
            sum += a;
        }

        bw.write(set.contains(c) ? "YES" : "NO");

        bw.flush();
        bw.close();
        br.close();
    }
}

 

 

10. C - Together

 

코드

import java.io.*;
import java.util.*;

public class Main {
    public static void add(HashMap<Integer, Integer> map, int n) {
        map.putIfAbsent(n, 0);
        map.replace(n, map.get(n) + 1);
    }

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        StringTokenizer st;

        int n = Integer.parseInt(br.readLine());
        st = new StringTokenizer(br.readLine());
        HashMap<Integer, Integer> map = new HashMap();

        for (int i = 0; i < n; i++) {
            int cur = Integer.parseInt(st.nextToken());
            add(map, cur - 1);
            add(map, cur);
            add(map, cur + 1);
        }

        int ans = 0;
        for (int x : map.values()) {
            ans = Math.max(ans, x);
        }

        bw.write(ans + "");

        bw.flush();
        bw.close();
        br.close();
    }
}