|
| 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 | + // 0: 아래, 1: 오른쪽, 2: 위, 3: 왼쪽 |
| 11 | + private static int[][] map; |
| 12 | + private static boolean[][][][][][] visited; |
| 13 | + private static int N; |
| 14 | +
|
| 15 | + public static void main(String[] args) throws IOException { |
| 16 | + init(); |
| 17 | + int answer = BFS(); |
| 18 | +
|
| 19 | + bw.write(answer + "\n"); |
| 20 | + bw.flush(); |
| 21 | + bw.close(); |
| 22 | + br.close(); |
| 23 | + } |
| 24 | +
|
| 25 | + private static void init() throws IOException { |
| 26 | + N = Integer.parseInt(br.readLine()); |
| 27 | + map = new int[N][N]; |
| 28 | + visited = new boolean[N][N][4][N][N][4]; |
| 29 | +
|
| 30 | + for (int i = 0; i < N; i++) { |
| 31 | + char[] input = br.readLine().toCharArray(); |
| 32 | + for (int j = 0; j < N; j++) { |
| 33 | + if (input[j] == 'H') { |
| 34 | + map[i][j] = 1; |
| 35 | + } |
| 36 | + } |
| 37 | + } |
| 38 | + } |
| 39 | +
|
| 40 | + private static int BFS() { |
| 41 | + Queue<int[]> q = new ArrayDeque<>(); |
| 42 | + int time = 0; |
| 43 | + visited[N-1][0][1][N-1][0][2] = true; |
| 44 | + q.add(new int[] {N-1, 0, 1, N-1, 0, 2, 0}); |
| 45 | +
|
| 46 | + while (!q.isEmpty()) { |
| 47 | + int[] current = q.poll(); |
| 48 | +
|
| 49 | + if (current[0] == 0 && current[1] == N-1 && current[3] == 0 && current[4] == N-1) { |
| 50 | + time = current[6]; |
| 51 | + break; |
| 52 | + } |
| 53 | +
|
| 54 | + int nx1, ny1, nx2, ny2; |
| 55 | + int dir1, dir2; |
| 56 | +
|
| 57 | + if (current[0] == 0 && current[1] == N-1) { |
| 58 | + nx1 = current[0]; |
| 59 | + ny1 = current[1]; |
| 60 | + } else { |
| 61 | + nx1 = current[0] + dx[current[2]]; |
| 62 | + ny1 = current[1] + dy[current[2]]; |
| 63 | + } |
| 64 | +
|
| 65 | + if (current[3] == 0 && current[4] == N-1) { |
| 66 | + nx2 = current[3]; |
| 67 | + ny2 = current[4]; |
| 68 | + } else { |
| 69 | + nx2 = current[3] + dx[current[5]]; |
| 70 | + ny2 = current[4] + dy[current[5]]; |
| 71 | + } |
| 72 | +
|
| 73 | + if (OOB(nx1, ny1) || map[nx1][ny1] == 1) { |
| 74 | + nx1 = current[0]; |
| 75 | + ny1 = current[1]; |
| 76 | + } |
| 77 | +
|
| 78 | + if (OOB(nx2, ny2) || map[nx2][ny2] == 1) { |
| 79 | + nx2 = current[3]; |
| 80 | + ny2 = current[4]; |
| 81 | + } |
| 82 | +
|
| 83 | + if (!visited[nx1][ny1][current[2]][nx2][ny2][current[5]]) { |
| 84 | + visited[nx1][ny1][current[2]][nx2][ny2][current[5]] = true; |
| 85 | + q.add(new int[] {nx1, ny1, current[2], nx2, ny2, current[5], current[6]+1}); |
| 86 | + } |
| 87 | +
|
| 88 | + dir1 = (current[2]+1) % 4; |
| 89 | + dir2 = (current[5]+1) % 4; |
| 90 | +
|
| 91 | + if (!visited[current[0]][current[1]][dir1][current[3]][current[4]][dir2]) { |
| 92 | + visited[current[0]][current[1]][dir1][current[3]][current[4]][dir2] = true; |
| 93 | + q.add(new int[] {current[0], current[1], dir1, current[3], current[4], dir2, current[6]+1}); |
| 94 | + } |
| 95 | +
|
| 96 | + dir1 = current[2]-1 < 0 ? 3 : current[2]-1; |
| 97 | + dir2 = current[5]-1 < 0 ? 3 : current[5]-1; |
| 98 | +
|
| 99 | + if (!visited[current[0]][current[1]][dir1][current[3]][current[4]][dir2]) { |
| 100 | + visited[current[0]][current[1]][dir1][current[3]][current[4]][dir2] = true; |
| 101 | + q.add(new int[] {current[0], current[1], dir1, current[3], current[4], dir2, current[6]+1}); |
| 102 | + } |
| 103 | +
|
| 104 | + } |
| 105 | +
|
| 106 | + return time; |
| 107 | + } |
| 108 | +
|
| 109 | + private static boolean OOB(int nx, int ny) { |
| 110 | + return nx < 0 || nx > N-1 || ny < 0 || ny > N-1; |
| 111 | + } |
| 112 | +} |
| 113 | +``` |
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