[20251110] BOJ / G4 / 좋은 수열 / 이준희

Author: JHLEE325

JHLEE325/202511/10 BOJ G4 좋은 수열.md

@@ -0,0 +1,41 @@
+```java
+import java.io.*;
+public class Main {
+    static int N;
+    static boolean found = false;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        N = Integer.parseInt(br.readLine().trim());
+        dfs("", 0);
+    }
+
+    static void dfs(String s, int depth) {
+        if (found) return;
+        if (depth == N) {
+            System.out.println(s);
+            found = true;
+            return;
+        }
+        for (int i = 1; i <= 3; i++) {
+            String ns = s + i;
+            if (goodString(ns)) {
+                dfs(ns, depth + 1);
+            }
+            if (found) return;
+        }
+    }
+
+    static boolean goodString(String s) {
+        int len = s.length();
+        for (int l = 1; l <= len / 2; l++) {
+            String a = s.substring(len - 2*l, len - l);
+            String b = s.substring(len - l, len);
+            if (a.equals(b)) {
+                return false;
+            }
+        }
+        return true;
+    }
+}
+```