检查具有偶数个数字的回文数是否为回文数

给定一个数字N，其中包含偶数个数字。任务是检查该数字是否为回文。
例子：

Input: N = 123321
Output: Palindrome

Input: 1234
Output: Not palindrome

天真的方法是从该数字的前后移动，并在不匹配的地方停止。
一种有效的方法是使用以下事实：

Palindrome Number having even number of digits is always divisible by 11.

假设数字是d1 d2 d3 d4…dn ，其中d1，d2，d3 ..是数字的数字。如果是回文，则d1 = dn，d2 = dn-1，d3 = dn-2…..依此类推。现在，由于11的可除性指出，数字的备用数字总和之差应为零，而回文数甚至为零的情况也应相同。的数字即

d1 + d3 + …+ dn-1 = d2 + d4 + d6 + … + dn 

因此，具有偶数位数的回文数始终可以被11整除。

C++

// C++ program to find number is palindrome
// or not without using any extra space
#include 
using namespace std;
 
// Function to check if the number is palindrome
bool isPalindrome(int n)
{
    // if divisible by 11 then true
    if (n % 11 == 0) {
        return true;
    }
 
    // if not divisible by 11
    return false;
}
 
// Driver code
int main()
{
    isPalindrome(123321) ? cout << "Palindrome"
                         : cout << "Not Palindrome";
    return 0;
}

Java

// Java program to find number
// is palindrome or not without
// using any extra space
class GFG
{
    // Function to check if the
    // number is palindrome
    static boolean isPalindrome(int n)
    {
        // if divisible by 11 then true
        if (n % 11 == 0)
        {
            return true;
        }
     
        // if not divisible by 11
        return false;
    }
     
    // Driver code
    public static void main(String[] args)
    {
        System.out.println(isPalindrome(123321) ?
                                   "Palindrome" :
                               "Not Palindrome");
    }
}
 
// This code is contributed by Bilal

Python3

# Python 3 program to find number is palindrome
# or not without using any extra space.
 
# Function to check if the number is palindrome
def isPalindrome(n) :
 
    # if divisible by 11 then return True
    if n % 11 == 0 :
        return True
 
    # if not divisible by 11 then return False
    return False
 
# Driver code
if __name__ == "__main__" :
 
    n = 123321
      
    if isPalindrome(n) :
        print("Palindrome")
    else :
        print("Not Palindrome")
             
# This code is contributed by ANKITRAI1

C#

// C# program to find number
// is palindrome or not without
// using any extra space
using System;
 
class GFG
{
    // Function to check if the
    // number is palindrome
    static bool isPalindrome(int n)
    {
        // if divisible by
        // 11 then true
        if (n % 11 == 0)
        {
            return true;
        }
     
        // if not divisible by 11
        return false;
    }
     
    // Driver code
    public static void Main()
    {
        Console.Write(isPalindrome(123321) ?
                              "Palindrome" :
                          "Not Palindrome");
    }
}
 
// This code is contributed
// by ChitraNayal

Javascript

 
// Javascript program to find number
// is palindrome or not without
// using any extra space
 
    // Function to check if the
    // number is palindrome
    function isPalindrome(n)
    {
        // if divisible by 11 then true
        if (n % 11 == 0)
        {
            return true;
        }
     
        // if not divisible by 11
        return false;
    }
     
    // Driver code
    document.write(isPalindrome(123321) ?
            "Palindrome" :
        "Not Palindrome");
 
// This code contributed by Princi Singh
 

输出：

Palindrome