백준 2573. 빙산 문제풀이 자바 JAVA

1BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
2StringTokenizer st = new StringTokenizer(br.readLine(), " ");
3
4N = Integer.parseInt(st.nextToken());
5M = Integer.parseInt(st.nextToken());
6
7graph = new int[N][M];
8
9for (int i = 0; i < N; i++) {
10    StringTokenizer temp = new StringTokenizer(br.readLine(), " ");
11    for (int j = 0; j < M; j++) {
12        graph[i][j] = Integer.parseInt(temp.nextToken());
13    }
14}

1private static class Info {
2    int x;
3    int y;
4    public Info(int x, int y) {
5        this.x = x;
6        this.y = y;
7    }
8
9    public int getX() {
10        return x;
11    }
12
13    public int getY() {
14        return y;
15    }
16}

1import java.io.BufferedReader;
2import java.io.IOException;
3import java.io.InputStreamReader;
4import java.util.*;
5
6public class Main {
7	static int N, M;
8	static boolean[][] check;
9	static int[][] graph;
10	static int[] moveX = {-1, 1, 0, 0};
11	static int[] moveY = {0, 0, -1, 1};
12
13	public static void main(String[] args) throws IOException {
14		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
15		StringTokenizer st = new StringTokenizer(br.readLine(), " ");
16
17		N = Integer.parseInt(st.nextToken());
18		M = Integer.parseInt(st.nextToken());
19
20		graph = new int[N][M];
21
22		for (int i = 0; i < N; i++) {
23			StringTokenizer temp = new StringTokenizer(br.readLine(), " ");
24			for (int j = 0; j < M; j++) {
25				graph[i][j] = Integer.parseInt(temp.nextToken());
26			}
27		}
28		int result = 0;
29
30		loop:
31		while (true) {
32			int cnt = 0;
33			check = new boolean[N][M];
34
35			for (int i = 0; i < N; i++) {
36				for (int j = 0; j < M; j++) {
37					if (cnt >= 2) break loop;
38					// i j 를 순환하며 BFS
39					if (graph[i][j] != 0 && !check[i][j]) {
40						BFS(new Info(i, j));
41						cnt++;
42					}
43				}
44			}
45
46			// 분리되지 않는 경우
47			if (cnt == 0) {
48				result = 0;
49				break;
50			}
51
52			result++;
53		}
54
55		System.out.print(result);
56	}
57
58	private static void BFS(Info info) {
59		Queue<Info> queue = new LinkedList<>();
60
61		queue.offer(info);
62		check[info.getX()][info.getY()] = true;
63
64		while (!queue.isEmpty()) {
65			int len = queue.size();
66
67			for (int i = 0; i < len; i++) {
68
69				Info poll = queue.poll();
70
71				int x = poll.getX();
72				int y = poll.getY();
73
74				for (int j = 0; j < 4; j++) {
75					int tempX = x + moveX[j];
76					int tempY = y + moveY[j];
77
78					if (tempX >= 0 && tempX < N && tempY >= 0 && tempY < M ) {
79						if (!check[tempX][tempY]) { // 방문한적 없는 노드일 때 (탐색하는 경우)
80							if (graph[tempX][tempY] == 0) { // 해당 노드가 0일때 (녹는 경우)
81								int value = graph[x][y];
82								if (value != 0) graph[x][y] = --value;
83								continue;
84							}
85
86							check[tempX][tempY] = true;
87							queue.offer(new Info(tempX, tempY));
88						}
89					}
90				}
91			}
92		}
93	}
94
95	private static class Info {
96		int x;
97		int y;
98		public Info(int x, int y) {
99			this.x = x;
100			this.y = y;
101		}
102
103		public int getX() {
104			return x;
105		}
106
107		public int getY() {
108			return y;
109		}
110	}
111}