[20260224] BOJ / G5 / A와 B 2 / 김민진

zinnnn37/202602/24 BOJ G5 A와 B 2.md

@@ -0,0 +1,50 @@
+```java
+import java.io.*;
+
+public class BJ_12919_A와_B_2 {
+
+    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    res;
+    private static String from, to;
+
+    public static void main(String[] args) throws IOException {
+        init();
+        sol();
+    }
+
+    private static void init() throws IOException {
+        from = br.readLine();
+        to = br.readLine();
+    }
+
+    private static void sol() throws IOException {
+        bw.write(rec(to) + "");
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+
+    private static int rec(String to) throws IOException {
+        if (from.equals(to)) {
+            return 1;
+        }
+
+        if (to.length() < from.length()) {
+            return 0;
+        }
+
+        if (to.charAt(to.length() - 1) == 'A') {
+            res = rec(to.substring(0, to.length() - 1));
+        }
+
+        if (to.charAt(0) == 'B') {
+            StringBuilder tmp = new StringBuilder(to.substring(1));
+            res = Math.max(res, rec(tmp.reverse().toString()));
+        }
+        return res;
+    }
+
+}
+```