Determining whether the string is a palindrome - Recursive

First, determine whether a string is a palindrome, implemented by recursive method.

Second, the general idea:

1, an input character string;

2, to compare the corresponding character string stored in the character array before and after then;

3, until the meet last remaining one or zero characters, is a palindrome;

Third, the source code:

 1 package org.yuan.Day2;
 2 
 3 import java.util.Scanner;
 4 
 5 public class Palindrome {
 6        
 7         public static void main(String[] args) {
 8             System.out.println("请输入一个字符串：");
 9             Scanner  sc=new Scanner(System.in);
10             String s = sc.next();
11             boolean huiwen = palindrom(s, 0 , s.length() );
12             System.out.println(huiwen);
13             sc.close();
14          }
 15          public  static  Boolean palindrom (S String, int I, int length) {
 16              IF (length-2. 1 == * I-2 * I || length == 0 )
 . 17                  return  to true ; // if satisfied to the last The number of remaining characters is 1 or 0, it is a palindromic 
18 is              IF ((s.toCharArray () [I]! = s.toCharArray () [I-length-1]) || (I> = 1 length- -i)) { // the string into a character array, before and after the corresponding characters are equal 
. 19                  return  to false ;
 20 is              }
 21 is              return palindrom (S, I ++, length); // recursive 
22          }
23 }
24     

IV Summary:

That calls itself recursively, repeat the same steps, but there are restrictions can to end this recursive function. Recursion can be a complex problem into a small problem, greatly reducing the amount of code.