Merge pull request #2064 from AlgorithmWithGod/zinnnn37

[20260409] BOJ / G3 / 불! / 김민진

Author: ShinHeeEul

zinnnn37/202604/9 BOJ G3 불!.md

@@ -0,0 +1,112 @@
+```java
+import java.io.*;
+import java.util.ArrayDeque;
+import java.util.Queue;
+import java.util.StringTokenizer;
+
+public class BJ_4179_불 {
+
+    private static final int[] dx = { -1, 1, 0, 0 };
+    private static final int[] dy = { 0, 0, -1, 1 };
+
+    private static final BufferedReader  br = new BufferedReader(new InputStreamReader(System.in));
+    private static final BufferedWriter  bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    private static       StringTokenizer st;
+
+    private static int R, C;
+    private static char[][]    matrix;
+    private static Queue<Node> q;
+    private static boolean[][] visited;
+
+    private static class Node {
+        int x;
+        int y;
+        int cnt;
+
+        public Node(int x, int y, int cnt) {
+            this.x = x;
+            this.y = y;
+            this.cnt = cnt;
+        }
+
+    }
+
+    public static void main(String[] args) throws IOException {
+        init();
+        sol();
+
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+
+    private static void init() throws IOException {
+        st = new StringTokenizer(br.readLine());
+        R = Integer.parseInt(st.nextToken());
+        C = Integer.parseInt(st.nextToken());
+
+        matrix = new char[R][C];
+        visited = new boolean[R][C];
+        q = new ArrayDeque<>();
+        for (int i = 0; i < R; i++) {
+            String line = br.readLine();
+            for (int j = 0; j < C; j++) {
+                matrix[i][j] = line.charAt(j);
+                if (matrix[i][j] == 'J') {
+                    q.offer(new Node(i, j, 0));
+                    visited[i][j] = true;
+                }
+            }
+        }
+
+        for (int i = 0; i < R; i++) {
+            for (int j = 0; j < C; j++) {
+                if (matrix[i][j] == 'F') {
+                    q.offer(new Node(i, j, -1));
+                }
+            }
+        }
+    }
+
+    private static void sol() throws IOException {
+        while (!q.isEmpty()) {
+            Node cur = q.poll();
+
+            // 지훈이의 현위치까지 불이 번진 경우
+            if (cur.cnt >= 0 && matrix[cur.x][cur.y] == 'F') continue;
+
+            for (int d = 0; d < 4; d++) {
+                int nx = cur.x + dx[d];
+                int ny = cur.y + dy[d];
+
+                // 지훈이만
+                if (OOB(nx, ny) && cur.cnt >= 0) {
+                    bw.write(cur.cnt + 1 + "");
+                    return;
+                }
+
+                if (OOB(nx, ny) || matrix[nx][ny] == 'F' || matrix[nx][ny] == '#') {
+                    continue;
+                }
+
+                // 지훈이 이동 가능 여부
+                if (cur.cnt >= 0 && visited[nx][ny]) continue;
+
+                if (matrix[cur.x][cur.y] == 'F') {
+                    matrix[nx][ny] = 'F';
+                    q.offer(new Node(nx, ny, -1));
+                } else {
+                    visited[nx][ny] = true;
+                    q.offer(new Node(nx, ny, cur.cnt + 1));
+                }
+            }
+        }
+        bw.write("IMPOSSIBLE");
+    }
+
+    private static boolean OOB(int x, int y) {
+        return x < 0 || R <= x || y < 0 || C <= y;
+    }
+
+}
+```