|
| 1 | +``` |
| 2 | +import java.io.*; |
| 3 | +import java.util.*; |
| 4 | +
|
| 5 | +public class Main { |
| 6 | + private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); |
| 7 | + private static final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); |
| 8 | + private static final int[] dx = {1, 0, -1, 0}; |
| 9 | + private static final int[] dy = {0, 1, 0, -1}; |
| 10 | + private static char[][] map; |
| 11 | + private static boolean[][][] visited; |
| 12 | + private static int[] start, end; |
| 13 | + private static int N, M, count; |
| 14 | + public static void main(String[] args) throws IOException { |
| 15 | + init(); |
| 16 | + int answer = BFS(); |
| 17 | +
|
| 18 | + bw.write(answer + "\n"); |
| 19 | + bw.flush(); |
| 20 | + bw.close(); |
| 21 | + br.close(); |
| 22 | + } |
| 23 | +
|
| 24 | + private static void init() throws IOException { |
| 25 | + StringTokenizer st = new StringTokenizer(br.readLine()); |
| 26 | + N = Integer.parseInt(st.nextToken()); |
| 27 | + M = Integer.parseInt(st.nextToken()); |
| 28 | +
|
| 29 | + map = new char[M][N]; |
| 30 | + start = new int[2]; |
| 31 | + end = new int[2]; |
| 32 | +
|
| 33 | + for (int i = 0; i < M; i++) { |
| 34 | + map[i] = br.readLine().toCharArray(); |
| 35 | + for (int j = 0; j < N; j++) { |
| 36 | + if (map[i][j] == 'S') { |
| 37 | + start[0] = i; |
| 38 | + start[1] = j; |
| 39 | + } else if (map[i][j] == 'E') { |
| 40 | + end[0] = i; |
| 41 | + end[1] = j; |
| 42 | + } else if (map[i][j] == 'X') { |
| 43 | + map[i][j] = (char) (count + '0'); |
| 44 | + count++; |
| 45 | + } |
| 46 | + } |
| 47 | + } |
| 48 | +
|
| 49 | + visited = new boolean[M][N][1 << count]; |
| 50 | + } |
| 51 | +
|
| 52 | + private static int BFS() { |
| 53 | + Queue<int[]> q = new ArrayDeque<>(); |
| 54 | + int result = 0; |
| 55 | + visited[start[0]][start[1]][0] = true; |
| 56 | + q.add(new int[]{start[0], start[1], 0, 0}); |
| 57 | +
|
| 58 | + while (!q.isEmpty()) { |
| 59 | + int[] current = q.poll(); |
| 60 | +
|
| 61 | + if (current[0] == end[0] && current[1] == end[1] && current[2] == (1 << count)-1) { |
| 62 | + result = current[3]; |
| 63 | + break; |
| 64 | + } |
| 65 | +
|
| 66 | + for (int i = 0; i < 4; i++) { |
| 67 | + int nx = current[0] + dx[i]; |
| 68 | + int ny = current[1] + dy[i]; |
| 69 | +
|
| 70 | + if (OOB(nx, ny) || map[nx][ny] == '#') continue; |
| 71 | +
|
| 72 | + if (!isThings(nx, ny) && !visited[nx][ny][current[2]]) { |
| 73 | + visited[nx][ny][current[2]] = true; |
| 74 | + q.add(new int[]{nx, ny, current[2], current[3]+1}); |
| 75 | + } else if (isThings(nx, ny)) { |
| 76 | + int v = 1 << (map[nx][ny] - '0'); |
| 77 | + if (visited[nx][ny][current[2] | v]) continue; |
| 78 | + visited[nx][ny][current[2] | v] = true; |
| 79 | + q.add(new int[]{nx, ny, current[2] | v, current[3] + 1}); |
| 80 | + } |
| 81 | +
|
| 82 | + } |
| 83 | + } |
| 84 | +
|
| 85 | + return result; |
| 86 | + } |
| 87 | +
|
| 88 | + private static boolean OOB(int nx, int ny) { |
| 89 | + return nx < 0 || nx > M-1 || ny < 0 || ny > N-1; |
| 90 | + } |
| 91 | +
|
| 92 | + private static boolean isThings(int nx, int ny) { |
| 93 | + return map[nx][ny] != '#' && |
| 94 | + map[nx][ny] != 'S' && |
| 95 | + map[nx][ny] != 'E' && |
| 96 | + map[nx][ny] != '.'; |
| 97 | + } |
| 98 | +} |
| 99 | +``` |
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