Check if a palindromic string can be obtained by concatenating substrings split from same indices of two given strings

// Java program for the above approach

import java.io.*;
import java.util.*;

class GFG {

    // Function to check if a string
    // is palindrome or not
    static boolean isPalindrome(String str)
    {

        // Start and end of the string
        int i = 0, j = str.length() - 1;

        // Iterate the string until i > j
        while (i < j) {

            // If there is a mismatch
            if (str.charAt(i)
                != str.charAt(j))
                return false;

            // Increment first pointer and
            // decrement the other
            i++;
            j--;
        }

        // Given string is a palindrome
        return true;
    }

    // Function two check if the strings can
    // be combined to form a palindrome
    static void formPalindrome(
        String a, String b, int n)
    {
        // Initialize array of characters
        char aa[] = new char[n + 2];
        char bb[] = new char[n + 2];

        Arrays.fill(aa, ' ');
        Arrays.fill(bb, ' ');

        // Stores character of string
        // in the character array
        for (int i = 1; i <= n; i++) {
            aa[i] = a.charAt(i - 1);
            bb[i] = b.charAt(i - 1);
        }

        boolean ok = false;

        for (int i = 0; i <= n + 1; i++) {

            // Find left and right parts
            // of strings a and b
            StringBuilder la
                = new StringBuilder();
            StringBuilder ra
                = new StringBuilder();
            StringBuilder lb
                = new StringBuilder();
            StringBuilder rb
                = new StringBuilder();

            for (int j = 1;
                 j <= i - 1; j++) {

                // Substring a[j...i-1]
                la.append((aa[j] == ' ')
                              ? ""
                              : aa[j]);

                // Substring b[j...i-1]
                lb.append((bb[j] == ' ')
                              ? ""
                              : bb[j]);
            }

            for (int j = i;
                 j <= n + 1; j++) {

                // Substring a[i...n]
                ra.append((aa[j] == ' ')
                              ? ""
                              : aa[j]);

                // Substring b[i...n]
                rb.append((bb[j] == ' ')
                              ? ""
                              : bb[j]);
            }

            // Check is left part of a +
            // right part of b or vice
            // versa is a palindrome
            if (isPalindrome(la.toString()
                             + rb.toString())
                || isPalindrome(lb.toString()
                                + ra.toString())) {
                ok = true;
                break;
            }
        }

        // Print the result
        if (ok)
            System.out.println("Yes");

        // Otherwise
        else
            System.out.println("No");
    }

    // Driver Code
    public static void main(String[] args)
    {
        String A = "bdea";
        String B = "abbb";

        int N = 4;

        formPalindrome(A, B, N);
    }
}

// Java program to implement
// the above approach
import java.util.*;
import java.io.*;

class GFG{
    
public static String rev(String str)
{
    int st = 0;
    int ed = str.length() - 1;
    char[] s = str.toCharArray();
    
    while(st < ed)
    {
        char temp = s[st];
        s[st] = s[ed];
        s[ed] = temp;
        st++;
        ed--;
    }
    return (s.toString());
}
  
public static boolean check(String a, 
                            String b, int n)
{
    int i = 0;
    int j = n - 1;
    
    // Iterate through the 
    // length if we could 
    // find a[i]==b[j] we could
    // increment I and decrement j
    while(i < n)
    {
        if (a.charAt(i) != b.charAt(j))
            break;
        
        // Else we could just break
        // the loop as its not a 
        // palindrome type sequence
        i += 1;
        j -= 1;
        
        // We could concatenate the 
        // a's left part +b's right 
        // part in a variable a and 
        // a's right part+b's left 
        // in the variable b
        String xa = a.substring(i, j + 1);
        String xb = b.substring(i, j + 1);
        
        // We would check for the 
        // palindrome condition if 
        // yes we print True else False
        StringBuffer XA = new StringBuffer(xa);
        XA.reverse();
        StringBuffer XB = new StringBuffer(xb);
        XB.reverse();
        
        if (xa == XA.toString() || 
            xb == XB.toString())
        {
            return true;
        }
    }
    return false;
}

// Driver Code
public static void main(String[] args) 
{
    String a = "xbdef";
    String b = "cabex";
    
    if (check(a, b, a.length()) || 
        check(b, a, a.length()))
        System.out.println("True");
    else
        System.out.println("False");
}
}

// This code is contributed by divyesh072019

import java.util.*;

public class Main 
{
  
    /*function to check if a string is palindrome or not*/
    public static boolean isPalindrome(String s)
    {
        int i = 0, j = s.length() - 1;
        while (i <= j) {
            if (s.charAt(i) != s.charAt(j)) {
                return false;
            }
            i++;
            j--;
        }
        return true;
    }

    public static boolean checkStrings(String a, String b,
                                       int n)
    {
        for (int i = 0; i < n; i++) {
            /*check whether the concatenation of substrings
             * is palindrome or not*/
            if ((isPalindrome(a.substring(0, i)
                              + b.substring(i)))
                || (isPalindrome(b.substring(0, i)
                                 + a.substring(i)))) {
                return true;
            }
        }

        return false;
    }

    public static void main(String[] args)
    {
        String a = "xyzdef";
        String b = "rstzyx";
        int n = 6;

        /*if the concatenation of substring is palindrome,
         * print true else print false*/
        if (checkStrings(a, b, n)) {
            System.out.println("true");
        }
        else {
            System.out.println("false");
        }
    }
}