Analyzing palindrome

Analyzing palindrome

I, entitled: string determines whether the input palindromic series.

Second, the design ideas:

1, an initial determination if the length of the string is 0 or 1, it must be returned directly palindromic exit.

2, write termination condition, if the last remaining one is a palindrome Back to exit. If it is two to determine whether They are equal if f is equal to 1 or f 0, returns an exit.

3, write normal circumstances, if the ending is equal to n plus 1, calls itself, if not equal before and after the middle of f 0, returns an exit.

Third, the source code:

import java.util.Scanner;

public class Huiwen {
    static char []a=new char[1000];
    static String str;
    static int f=0;
    static int n=0;
    static Scanner sc=new Scanner(System.in);
    public static void main(String[] args) {
        str=sc.nextLine();
        a=str.toCharArray();
        huiWen(a,n);
        if(f==0) {
            System.out.println (STR + ":" + "is not a palindrome" ); 
        } 
        the else { 
            System.out.println (STR + ":" + "palindromic sequence" ); 
        } 
    } 
    public  static  void Huiwen ( char [] A, int n-) {
         IF (a.length a.length == == 0 ||. 1 ) { 
            F =. 1 ;
             return ; 
        } 
        IF (a.length-2-n-* ==. 1. 1 ) { 
            F =. 1 ;
             return ; 
        } 
        IF(a.length-2*n-1==2) {
            if(a[n]==a[a.length-n-1]) {
                f=1;
                return ;
            }
            else {
                f=0;
                return ;
            }
        }
        
        if(a[n]==a[a.length-n-1]) {
            n=n+1;
            huiWen(a,n);
            
        }
        else {
            f=0;
            return ;
        }
        
    }

}

Fourth, the test results

 

 

 

 

 

 

 

 

 V. Conclusion:

Recursive three elements:

1, an unequivocal end to conditions, given that the end of the recursive approach.

2, the result of extraction problem, reduce the size of the problem.

3, calls itself.