[20250723] BOJ / G5 / 방탈출 / 신동윤

03do-new30/202507/23 BOJ G5 방탈출.md

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+```java
+import java.util.*;
+import java.io.*;
+
+public class Main {
+    static int N, M;
+    static int[][] arr;
+    static int maxPath, password;
+    static int[] dr = {0, 0, -1, 1};
+    static int[] dc = {-1, 1, 0, 0};
+    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());
+        arr = new int[N][M];
+        for (int i = 0; i < N; i++) {
+            st = new StringTokenizer(br.readLine());
+            for (int j = 0; j < M; j++) {
+                arr[i][j] = Integer.parseInt(st.nextToken());
+            }
+        }
+
+        maxPath = 0;
+        password = 0;
+        for (int i = 0; i < N; i++) {
+            for (int j = 0; j < M; j++) {
+                if (arr[i][j] > 0) {
+                    bfs(i, j);
+                }
+            }
+        }
+        System.out.println(password);
+        br.close();
+    }
+
+    private static void bfs(int r, int c) {
+        boolean[][] visited = new boolean[N][M];
+        Deque<int[]> dq = new ArrayDeque<>();
+        dq.offerLast(new int[] {r, c, 1});
+        visited[r][c] = true;
+        int start = arr[r][c];
+
+        while (!dq.isEmpty()) {
+            int[] rc = dq.pollFirst();
+            r = rc[0];
+            c = rc[1];
+            int path = rc[2];
+
+            boolean hasNextPath = false;
+            for (int i = 0; i < 4; i++) {
+                int nr = r + dr[i];
+                int nc = c + dc[i];
+                if (nr < 0 || nr >= N || nc < 0 || nc >= M) continue;
+                if (visited[nr][nc]) continue;
+                if (arr[nr][nc] == 0) continue;
+                hasNextPath = true;
+                visited[nr][nc] = true;
+                dq.offerLast(new int[] {nr, nc, path + 1});
+            }
+
+            if (!hasNextPath) {
+                if (path > maxPath) {
+                    maxPath = path;
+                    password = start + arr[r][c];
+                } else if (path == maxPath) {
+                    password = Math.max(password, start + arr[r][c]);
+                }
+            }
+        }
+    }
+}
+
+```