[20251226] BOJ / G4 / 미로만들기 / 김민진

zinnnn37/202512/26 BOJ G4 미로만들기.md

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+```java
+package etc;
+
+import java.io.*;
+import java.util.ArrayDeque;
+import java.util.Arrays;
+import java.util.Deque;
+
+public class BJ_2665_미로만들기 {
+
+    private static final int[] dx = { 0, 0, -1, 1 };
+    private static final int[] dy = { -1, 1, 0, 0 };
+
+    private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    private static final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+    private static int         N;
+    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 {
+        init();
+        sol();
+    }
+
+    private static void init() throws IOException {
+        N = Integer.parseInt(br.readLine());
+
+        matrix = new char[N][N];
+        for (int i = 0; i < N; i++) {
+            String s = br.readLine();
+            for (int j = 0; j < N; j++) {
+                matrix[i][j] = s.charAt(j);
+            }
+        }
+
+        dist = new int[N][N];
+        for (int[] row : dist) {
+            Arrays.fill(row, Integer.MAX_VALUE);
+        }
+
+        dq = new ArrayDeque<>();
+    }
+
+    private static void sol() throws IOException {
+        dq.offer(new Node(0, 0, 0));
+        dist[0][0] = 0;
+
+        while (!dq.isEmpty()) {
+            Node cur = dq.poll();
+
+            if (cur.x == N - 1 && cur.y == N - 1) {
+                bw.write(cur.cnt + "");
+                bw.flush();
+                bw.close();
+                br.close();
+                return;
+            }
+
+            if (cur.cnt > dist[cur.x][cur.y]) continue;
+
+            for (int d = 0; d < 4; d++) {
+                int nx = cur.x + dx[d];
+                int ny = cur.y + dy[d];
+
+                if (OOB(nx, ny)) continue;
+
+                int newCost = cur.cnt + (matrix[nx][ny] == '0' ? 1 : 0);
+
+                if (newCost < dist[nx][ny]) {
+                    dist[nx][ny] = newCost;
+
+                    if (matrix[nx][ny] == '1') {
+                        dq.offerFirst(new Node(nx, ny, newCost));
+                    } else {
+                        dq.offerLast(new Node(nx, ny, newCost));
+                    }
+                }
+            }
+        }
+    }
+
+    private static boolean OOB(int x, int y) {
+        return x < 0 || N <= x || y < 0 || N <= y;
+    }
+
+}
+```