|
| 1 | +```java |
| 2 | +import java.io.*; |
| 3 | +import java.util.*; |
| 4 | + |
| 5 | +public class Main { |
| 6 | + static int R, C; |
| 7 | + static char[][] map; |
| 8 | + static int[][] fireTime; |
| 9 | + static int[][] personTime; |
| 10 | + static int[] dx = {-1, 1, 0, 0}; |
| 11 | + static int[] dy = {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 | + R = Integer.parseInt(st.nextToken()); |
| 18 | + C = Integer.parseInt(st.nextToken()); |
| 19 | + |
| 20 | + map = new char[R][C]; |
| 21 | + fireTime = new int[R][C]; |
| 22 | + personTime = new int[R][C]; |
| 23 | + |
| 24 | + Deque<int[]> fireQueue = new ArrayDeque<>(); |
| 25 | + Deque<int[]> personQueue = new ArrayDeque<>(); |
| 26 | + |
| 27 | + for (int i = 0; i < R; i++) { |
| 28 | + Arrays.fill(fireTime[i], -1); |
| 29 | + Arrays.fill(personTime[i], -1); |
| 30 | + } |
| 31 | + |
| 32 | + for (int i = 0; i < R; i++) { |
| 33 | + String line = br.readLine(); |
| 34 | + for (int j = 0; j < C; j++) { |
| 35 | + map[i][j] = line.charAt(j); |
| 36 | + if (map[i][j] == 'F') { |
| 37 | + fireQueue.offer(new int[]{i, j}); |
| 38 | + fireTime[i][j] = 0; |
| 39 | + } else if (map[i][j] == 'J') { |
| 40 | + personQueue.offer(new int[]{i, j}); |
| 41 | + personTime[i][j] = 0; |
| 42 | + } |
| 43 | + } |
| 44 | + } |
| 45 | + |
| 46 | + while (!fireQueue.isEmpty()) { |
| 47 | + int[] current = fireQueue.poll(); |
| 48 | + int x = current[0]; |
| 49 | + int y = current[1]; |
| 50 | + |
| 51 | + for (int i = 0; i < 4; i++) { |
| 52 | + int nx = x + dx[i]; |
| 53 | + int ny = y + dy[i]; |
| 54 | + |
| 55 | + if (nx < 0 || nx >= R || ny < 0 || ny >= C) continue; |
| 56 | + if (map[nx][ny] == '#' || fireTime[nx][ny] != -1) continue; |
| 57 | + |
| 58 | + fireTime[nx][ny] = fireTime[x][y] + 1; |
| 59 | + fireQueue.offer(new int[]{nx, ny}); |
| 60 | + } |
| 61 | + } |
| 62 | + |
| 63 | + while (!personQueue.isEmpty()) { |
| 64 | + int[] current = personQueue.poll(); |
| 65 | + int x = current[0]; |
| 66 | + int y = current[1]; |
| 67 | + |
| 68 | + if (x == 0 || x == R-1 || y == 0 || y == C-1) { |
| 69 | + System.out.println(personTime[x][y] + 1); |
| 70 | + return; |
| 71 | + } |
| 72 | + |
| 73 | + for (int i = 0; i < 4; i++) { |
| 74 | + int nx = x + dx[i]; |
| 75 | + int ny = y + dy[i]; |
| 76 | + |
| 77 | + if (nx < 0 || nx >= R || ny < 0 || ny >= C) continue; |
| 78 | + if (map[nx][ny] == '#' || personTime[nx][ny] != -1) continue; |
| 79 | + |
| 80 | + int nextTime = personTime[x][y] + 1; |
| 81 | + |
| 82 | + if (fireTime[nx][ny] == -1 || fireTime[nx][ny] > nextTime) { |
| 83 | + personTime[nx][ny] = nextTime; |
| 84 | + personQueue.offer(new int[]{nx, ny}); |
| 85 | + } |
| 86 | + } |
| 87 | + } |
| 88 | + |
| 89 | + System.out.println("IMPOSSIBLE"); |
| 90 | + } |
| 91 | +} |
| 92 | +``` |
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