[20250228] BOJ / G3 / 소문난 칠공주 / 신동윤

03do-new30/202502/28 BOJ G3 소문난 칠공주.md

@@ -0,0 +1,73 @@
+```java
+import java.util.*;
+
+public class Main {
+    static int[] dr = {0, 0, -1, 1};
+    static int[] dc = {-1, 1, 0, 0};
+    static int answer;
+    static char[][] arr;
+    static int[] girls;
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        arr = new char[5][5];
+        for (int i = 0; i < 5; i++) {
+            arr[i] = sc.next().toCharArray();
+        }
+        girls = new int[7];
+        solve(0, 0, 0);
+        System.out.println(answer);
+        sc.close();
+    }
+
+    static void solve(int idx, int start, int sCount) {
+        if (idx == 7) {
+            if (sCount >= 4 && isValidGirls()) { answer++; }
+            return;
+        }
+
+        for (int i = start; i < 25; i++) {
+            int r = i / 5;
+            int c = i % 5;
+
+            girls[idx] = i;
+            if (arr[r][c] == 'S') {
+                solve(idx + 1, i + 1, sCount + 1);
+            } else {
+                solve(idx + 1, i + 1, sCount);
+            }
+        }
+    }
+
+    static boolean isValidGirls() {
+        Queue<Integer> q = new ArrayDeque<>();
+        boolean[] visited = new boolean[25];
+        q.offer(girls[0]);
+        visited[girls[0]] = true;
+        while (!q.isEmpty()) {
+            int x = q.poll();
+            int r = x / 5;
+            int c = x % 5;
+            for (int i = 0; i < 4; i++) {
+                int nr = r + dr[i];
+                int nc = c + dc[i];
+                int y = nr * 5 + nc;
+                if (nr < 0 || nr >= 5 || nc < 0 || nc >= 5) { continue; }
+                if (visited[y]) { continue; }
+                // girls에 포함된 경우에만 방문 표시
+                for (int idx = 0; idx < 7; idx++) {
+                    if (girls[idx] == y) {
+                        visited[y] = true;
+                        q.offer(y);
+                        break;
+                    }
+                }
+            }
+        }
+        for (int girl : girls) {
+            if (!visited[girl]) { return false;}
+        }
+        return true;
+
+    }
+}
+```