[20260124] BOJ / P4 / 탈옥 / 김민진

Author: zinnnn37

zinnnn37/202601/24 BOJ P4 탈옥.md

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+```java
+import java.io.*;
+import java.util.ArrayDeque;
+import java.util.Arrays;
+import java.util.Deque;
+import java.util.StringTokenizer;
+
+public class BJ_9376_탈옥 {
+
+    private static final int   INF = 10001;
+    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 final StringBuilder   sb = new StringBuilder();
+    private static       StringTokenizer st;
+
+    private static int H, W;
+    private static int[][]     prisoners;
+    private static int[][][]   dist;
+    private static char[][]    matrix;
+    private static Deque<Node> dq;
+
+    private static class Node {
+        int x;
+        int y;
+        int cnt;
+
+        Node(int x, int y, int cnt) {
+            this.x = x;
+            this.y = y;
+            this.cnt = cnt;
+        }
+
+    }
+
+    public static void main(String[] args) throws IOException {
+        int T = Integer.parseInt(br.readLine());
+
+        while (T-- > 0) {
+            init();
+            sol();
+        }
+
+        bw.write(sb.toString());
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+
+    private static void init() throws IOException {
+        st = new StringTokenizer(br.readLine());
+        H = Integer.parseInt(st.nextToken());
+        W = Integer.parseInt(st.nextToken());
+
+        prisoners = new int[2][2];
+        int idx = 0;
+
+        matrix = new char[H + 2][W + 2];
+        dist = new int[3][H + 2][W + 2];
+
+        for (int i = 0; i < H + 2; i++) {
+            Arrays.fill(dist[0][i], INF);
+            Arrays.fill(dist[1][i], INF);
+            Arrays.fill(dist[2][i], INF);
+            Arrays.fill(matrix[i], '.');
+        }
+
+        for (int i = 1; i <= H; i++) {
+            String line = br.readLine();
+            for (int j = 1; j <= W; j++) {
+                matrix[i][j] = line.charAt(j - 1);
+
+                if (matrix[i][j] == '$') {
+                    prisoners[idx][0] = i;
+                    prisoners[idx++][1] = j;
+                    matrix[i][j] = '.';
+                }
+            }
+        }
+
+        dq = new ArrayDeque<>();
+    }
+
+    private static void sol() {
+        bfs(0, 0, 0);
+        bfs(1, prisoners[0][0], prisoners[0][1]);
+        bfs(2, prisoners[1][0], prisoners[1][1]);
+
+        int ans = INF;
+        for (int i = 0; i < H + 2; i++) {
+            for (int j = 0; j < W + 2; j++) {
+                if (matrix[i][j] == '*') continue;
+
+                int sum = dist[0][i][j] + dist[1][i][j] + dist[2][i][j];
+                if (matrix[i][j] == '#') sum -= 2;
+
+                ans = Math.min(ans, sum);
+            }
+        }
+
+        sb.append(ans).append('\n');
+    }
+
+    private static void bfs(int id, int x, int y) {
+        dq.clear();
+        dq.offer(new Node(x, y, 0));
+        dist[id][x][y] = 0;
+
+        while (!dq.isEmpty()) {
+            Node cur = dq.poll();
+
+            if (dist[id][cur.x][cur.y] < cur.cnt) continue;
+
+            for (int d = 0; d < 4; d++) {
+                int nx = cur.x + dx[d];
+                int ny = cur.y + dy[d];
+
+                if (OOB(nx, ny) || matrix[nx][ny] == '*') continue;
+
+                int newDist = matrix[nx][ny] == '#' ? cur.cnt + 1 : cur.cnt;
+
+                if (newDist < dist[id][nx][ny]) {
+                    dist[id][nx][ny] = newDist;
+
+                    if (newDist == cur.cnt) {
+                        dq.offerFirst(new Node(nx, ny, newDist));
+                    } else {
+                        dq.offerLast(new Node(nx, ny, newDist));
+                    }
+                }
+            }
+        }
+    }
+
+    private static boolean OOB(int x, int y) {
+        return x < 0 || H + 2 <= x || y < 0 || W + 2 <= y;
+    }
+
+}
+```