Analyzing palindromic sequence (recursive)

　　Objective: to determine whether a string is a palindrome sequence.

　　code show as below:

 1 import java.util.Scanner;
 2 
 3 public class Palindrome {
 4     public static void main(String[] args) {
 5         Scanner in = new Scanner(System.in);
 6         String s = in.next();
 7         int n = s.length();
 8         if(n == 1||n == 0){
 9             System.out.println("该字符串回文");
10         }
11         else{
12             judge(s,0,n-1);
13         }
14         in.close();
15     }
16     
17     public static void judge(String a, int b, int c){
18         char c1 = a.charAt(b);
19         char c2 = a.charAt(c);
20         if(c1==c2){
21             if(c == b||c == b+1){
22                 System.out.println("该字符串回文");
23             }
24             else{
25                 judge(a,++b,--c);
26             }
 27          }
 28          the else {
 29              System.out.println ( "the string does not palindromes" );
 30          }
 31      }
 32  
33 is }

Method judge three parameters: String a character string input means; int b initially subscript string head, the method is performed once per time increment; int c subscript as an initial end of the string, the method is performed once per decrement once.

 

Specific implementation: the use of charAt read character string, respectively represent variables c1 and c2, then compared. Abort condition c == b (when the string length is an even number) or c == b + 1 c1 == c2 recursively calling the method (length of the string is odd), the suspension does not meet the conditions, and. Until the results.