[20251026] BOJ / G4 / 카드 섞기 / 김수연

Author: suyeun84

suyeun84/202510/26 BOJ G4 카드 섞기.md

@@ -0,0 +1,58 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class boj1091 {
+    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    static StringTokenizer st;
+    static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+    static int nextInt() {return Integer.parseInt(st.nextToken());}
+
+    static int N;
+    static int[] P, S, cur, start;
+    public static void main(String[] args) throws Exception {
+    	  int answer = 0;
+        nextLine();
+        N = nextInt();
+        nextLine();
+        P = new int[N];
+        cur = new int[N];
+        start = new int[N];
+        for (int i = 0; i < N; i++) {
+        	P[i] = nextInt();
+        	cur[i] = i;
+        }
+        start = cur.clone();
+        nextLine();
+        S = new int[N];
+        for (int i = 0; i < N; i++) S[i] = nextInt();
+        
+        if (check()) {
+            System.out.println(0);
+            return;
+        }
+        
+        while (true) {
+        	int[] temp = new int[N];
+        	for (int i = 0; i < N; i++) temp[S[i]] = cur[i];
+        	answer++;
+        	cur = temp;
+        	if (check()) break;
+        	if (Arrays.equals(cur, start)) {
+        		answer = -1;
+        		break;
+        	}
+        }
+        System.out.println(answer);
+    }
+    
+    static boolean check() {
+    	int[] pos = new int[N];
+        for (int i = 0; i < N; i++) pos[cur[i]] = i;
+    	for (int i = 0; i < N; i++) {
+    		if (pos[i] % 3 != P[i]) return false;
+    	}
+    	return true;
+    }
+}
+```