[20250312] BOJ / P5 / 순환 순열 / 신희을

Author: ShinHeeEul

ShinHeeEul/202503/12 BOJ 순환 순열.md

@@ -0,0 +1,64 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+	
+	
+	static int[] failure;
+	static int count = 0;
+    public static void main(String[] args) throws Exception{
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        
+        
+        String a = br.readLine();
+        a += a.substring(0, a.length() - 1);
+        String b = br.readLine();
+        
+        char[] ac = a.toCharArray();
+        char[] bc = b.toCharArray();
+        
+        failure = new int[ac.length];
+        
+        failureFunction(bc);
+        kmp(ac, bc);
+        System.out.println(count);
+    }
+    
+    public static void failureFunction(char[] s) {
+    	int p = 0;
+    	
+    	for(int idx = 1; idx < s.length; idx++) {
+    		
+    		while(p != 0  && s[idx] != s[p]) {
+    			p = failure[p - 1];
+    		}
+    		
+    		if(s[idx] == s[p]) {
+    			p++;
+    			failure[idx] = p;
+    		}
+    	}
+    	
+    }
+    
+    public static void kmp(char[] s1, char[] s2) {
+    	
+    	int p = 0;
+    	
+    	for(int idx = 0; idx < s1.length; idx++) {
+    		
+    		while(p != 0 && s1[idx] != s2[p]) p = failure[p - 1];
+    		
+    		if(s1[idx] == s2[p]) {
+    			if(p == s2.length - 1) {
+    				count++;
+    				p = failure[p];
+    			} else {
+    				p++;
+    			}
+    		}
+    	}
+    }
+}
+```