[20251112] BOJ / G5 / 보물섬 / 이준희

JHLEE325/202511/12 BOJ G5 보물섬.md

@@ -0,0 +1,75 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    static int N, M;
+    static int[][] map;
+    static int res = 0;
+    static int[] dy = {-1, 1, 0, 0};
+    static int[] dx = {0, 0, -1, 1};
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+
+        map = new int[N][M];
+
+        for (int i = 0; i < N; i++) {
+            String s = br.readLine();
+            for (int j = 0; j < M; j++) {
+                char c = s.charAt(j);
+                switch (c) {
+                    case 'W': {
+                        map[i][j] = 0;
+                        break;
+                    }
+                    case 'L': {
+                        map[i][j] = 1;
+                        break;
+                    }
+                }
+            }
+        }
+
+        for (int i = 0; i < N; i++) {
+            for (int j = 0; j < M; j++) {
+                if (map[i][j] == 1) {
+                    bfs(i, j);
+                }
+            }
+        }
+
+        System.out.println(res);
+    }
+
+    static void bfs(int y, int x) {
+        boolean[][] visited = new boolean[N][M];
+        Queue<int[]> q = new ArrayDeque<>();
+        visited[y][x] = true;
+        q.add(new int[]{y, x});
+        int temp = 0;
+
+        while (!q.isEmpty()) {
+            temp++;
+            int s = q.size();
+            for (int i = 0; i < s; i++) {
+                int[] cur = q.poll();
+                for (int d = 0; d < 4; d++) {
+                    int ny = cur[0] + dy[d];
+                    int nx = cur[1] + dx[d];
+                    if (ny < 0 || nx < 0 || ny >= N || nx >= M || visited[ny][nx] || map[ny][nx] == 0)
+                        continue;
+                    visited[ny][nx] = true;
+                    q.add(new int[]{ny, nx});
+                }
+            }
+        }
+        res = Math.max(res, temp - 1);
+    }
+}
+```