BOJ_2661 : 좋은수열

Author: spring0913

week12/BOJ_2661(좋은수열).java

@@ -0,0 +1,39 @@
+import java.io.*;
+
+public class Main {
+
+    private static int N;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        N = Integer.parseInt(br.readLine());
+        dfs("1");
+    }
+
+    public static void dfs(String strNum) {
+        if(strNum.length() == N) {
+            System.out.println(strNum);
+            System.exit(0);
+            return;
+        }
+
+        for(int j=1; j<=3; j++) {
+            String str = strNum + j;
+            if(check(str)) {
+                dfs(str);
+            }
+        }
+    }
+
+    public static boolean check(String strNum) {
+        int len = strNum.length();
+        for(int i=1; i<=len/2; i++) {
+            String str1 = strNum.substring(len-i, len);
+            String str2 = strNum.substring(len-i*2, len-i);
+            if(str1.equals(str2)) {
+                return false;
+            }
+        }
+        return true;
+    }
+}