[20251028] BOJ / G1 / 배달 / 한종욱

Author: Ukj0ng

Ukj0ng/202510/28 BOJ G1 배달.md

@@ -0,0 +1,87 @@
+```
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    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 int[] dx = {1, 0, -1, 0};
+    private static final int[] dy = {0, 1, 0, -1};
+    private static int[][] map;
+    private static boolean[][][][] visited;
+    private static int[] start;
+    private static int N, M;
+    public static void main(String[] args) throws IOException {
+        init();
+        int answer = BFS();
+
+        bw.write(answer + "\n");
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+
+    private static void init() throws IOException {
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+
+        map = new int[N][M];
+        visited = new boolean[N][M][4][4];
+        start = new int[2];
+
+        int count = 1;
+        for (int i = 0; i < N; i++) {
+            char[] input = br.readLine().toCharArray();
+            for (int j = 0; j < M; j++) {
+                if (input[j] == 'S') {
+                    start[0] = i;
+                    start[1] = j;
+                } else if (input[j] == '#') {
+                    map[i][j] = -1;
+                } else if (input[j] == 'C') {
+                    map[i][j] = count++;
+                }
+            }
+        }
+    }
+
+    private static int BFS() {
+        Queue<int[]> q = new ArrayDeque<>();
+        int result = -1;
+        for (int i = 0; i < 4; i++) {
+            visited[start[0]][start[1]][0][i] = true;
+            q.add(new int[]{start[0], start[1], 0, i, 0});
+        }
+
+        while (!q.isEmpty()) {
+            // x, y, C의 개수, 방향, 시간
+            int[] current = q.poll();
+
+            if (current[2] == 3) {
+                result = current[4];
+                break;
+            }
+
+            for (int i = 0; i < 4; i++) {
+                if (current[3] == i) continue;
+                int nx = current[0] + dx[i];
+                int ny = current[1] + dy[i];
+
+                if (OOB(nx, ny) || map[nx][ny] == -1) continue;
+                int nCount = current[2] | map[nx][ny];
+
+                if (nCount > 3 || visited[nx][ny][nCount][i]) continue;
+                visited[nx][ny][nCount][i] = true;
+                q.add(new int[]{nx, ny, nCount, i, current[4]+1});
+            }
+        }
+
+        return result;
+    }
+
+    private static boolean OOB(int nx, int ny) {
+        return nx < 0 || nx > N-1 || ny < 0 || ny > M-1;
+    }
+}
+```