[20260108] BOJ / P5 / 안대 낀 스피드러너 / 이강현

Author: lkhyun

lkhyun/202601/08 BOJ P5 안대 낀 스피드러너.md

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+```java
+import java.util.*;
+import java.io.*;
+
+public class Main {
+    static class State {
+        int x1, y1, dir1;
+        int x2, y2, dir2;
+        int steps;
+
+        State(int x1, int y1, int dir1, int x2, int y2, int dir2, int steps) {
+            this.x1 = x1;
+            this.y1 = y1;
+            this.dir1 = dir1;
+            this.x2 = x2;
+            this.y2 = y2;
+            this.dir2 = dir2;
+            this.steps = steps;
+        }
+    }
+
+    static int N;
+    static char[][] map;
+    static int[] dx = {-1, 0, 1, 0};
+    static int[] dy = {0, 1, 0, -1};
+
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        N = Integer.parseInt(br.readLine());
+        map = new char[N][N];
+
+        for (int i = 0; i < N; i++) {
+            String line = br.readLine();
+            for (int j = 0; j < N; j++) {
+                map[i][j] = line.charAt(j);
+            }
+        }
+
+        System.out.println(bfs());
+    }
+
+    public static int bfs() {
+        Queue<State> q = new LinkedList<>();
+        boolean[][][][][][] visited = new boolean[N][N][4][N][N][4];
+
+        State start = new State(N-1, 0, 0, N-1, 0, 1, 0);
+        q.offer(start);
+        visited[N-1][0][0][N-1][0][1] = true;
+
+        while (!q.isEmpty()) {
+            State cur = q.poll();
+
+            if (cur.x1 == 0 && cur.y1 == N-1 && cur.x2 == 0 && cur.y2 == N-1) {
+                return cur.steps;
+            }
+
+            int nx1 = cur.x1;
+            int ny1 = cur.y1;
+            int nx2 = cur.x2;
+            int ny2 = cur.y2;
+
+            if (!(cur.x1 == 0 && cur.y1 == N-1)) {
+                nx1 = cur.x1 + dx[cur.dir1];
+                ny1 = cur.y1 + dy[cur.dir1];
+                if (!isValid(nx1, ny1)) {
+                    nx1 = cur.x1;
+                    ny1 = cur.y1;
+                }
+            }
+
+            if (!(cur.x2 == 0 && cur.y2 == N-1)) {
+                nx2 = cur.x2 + dx[cur.dir2];
+                ny2 = cur.y2 + dy[cur.dir2];
+                if (!isValid(nx2, ny2)) {
+                    nx2 = cur.x2;
+                    ny2 = cur.y2;
+                }
+            }
+
+            if (!visited[nx1][ny1][cur.dir1][nx2][ny2][cur.dir2]) {
+                visited[nx1][ny1][cur.dir1][nx2][ny2][cur.dir2] = true;
+                q.offer(new State(nx1, ny1, cur.dir1, nx2, ny2, cur.dir2, cur.steps + 1));
+            }
+
+            int newDir1 = (cur.dir1 + 3) % 4;
+            int newDir2 = (cur.dir2 + 3) % 4;
+
+            if (!visited[cur.x1][cur.y1][newDir1][cur.x2][cur.y2][newDir2]) {
+                visited[cur.x1][cur.y1][newDir1][cur.x2][cur.y2][newDir2] = true;
+                q.offer(new State(cur.x1, cur.y1, newDir1, cur.x2, cur.y2, newDir2, cur.steps + 1));
+            }
+
+            newDir1 = (cur.dir1 + 1) % 4;
+            newDir2 = (cur.dir2 + 1) % 4;
+
+            if (!visited[cur.x1][cur.y1][newDir1][cur.x2][cur.y2][newDir2]) {
+                visited[cur.x1][cur.y1][newDir1][cur.x2][cur.y2][newDir2] = true;
+                q.offer(new State(cur.x1, cur.y1, newDir1, cur.x2, cur.y2, newDir2, cur.steps + 1));
+            }
+        }
+
+        return -1;
+    }
+
+    static boolean isValid(int x, int y) {
+        return x >= 0 && x < N && y >= 0 && y < N && map[x][y] == 'E';
+    }
+}
+```