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Reverse and Add Function
• Difficulty Level : Easy
• Last Updated : 29 Jan, 2019

The reverse and add function starts with a number, reverses its digits, and adds the reverse to the original. If the sum is not a palindrome, repeat this procedure until it does.

Write a program that takes number and gives the resulting palindrome (if one exists). If it took more than 1,000 iterations (additions) or yield a palindrome that is greater than 4,294,967,295, assume that no palindrome exist for the given number.

Examples:

```Input : 195
Output : 9339

Input : 265
Output: 45254

Input : 196
Output : No palindrome exist

```

## C++

 `// C++ Program to implement reverse and add function``#include``using` `namespace` `std;`` ` `/* Iterative function to reverse digits of num*/``long` `long` `reversDigits(``long` `long` `num)``{``    ``long` `long` `rev_num = 0;``    ``while` `(num > 0)``    ``{``        ``rev_num = rev_num*10 + num%10;``        ``num = num/10;``    ``}``    ``return` `rev_num;``}`` ` `/* Function to check whether he number is palindrome or not */``bool` `isPalindrome(``long` `long` `num)``{``    ``return` `(reversDigits(num) == num);``}`` ` `/* Reverse and Add Function */``void` `ReverseandAdd(``long` `long` `num)``{``    ``long` `long` `rev_num=0;``    ``while` `(num <= 4294967295)``    ``{``        ``// Reversing the digits of the number``        ``rev_num = reversDigits(num);`` ` `        ``// Adding the reversed number with the original``        ``num = num + rev_num;`` ` `        ``// Checking whether the number is palindrome or not``        ``if` `(isPalindrome(num))``        ``{``            ``printf``(``"%lld\n"``,num);``            ``break``;``        ``}``        ``else` `if` `(num > 4294967295)``        ``{``            ``printf``(``"No palindrome exist"``);``        ``}``    ``}``}`` ` `// Driver Program``int` `main()``{``    ``ReverseandAdd(195);``    ``ReverseandAdd(265);``    ``return` `0;``}`

## Java

 `// Java Program to implement reverse and add function``public` `class` `ReverseAdd ``{``    ``/* Iterative function to reverse digits of num*/``    ``long` `reversDigits(``long` `num)``    ``{``        ``long` `rev_num = ``0``;``        ``while` `(num > ``0``)``        ``{``            ``rev_num = rev_num*``10` `+ num%``10``;``            ``num = num/``10``;``        ``}``        ``return` `rev_num;``    ``}`` ` `    ``/* Function to check whether he number is``           ``palindrome or not */``    ``boolean` `isPalindrome(``long` `num)``    ``{``        ``return` `(reversDigits(num) == num);``    ``}`` ` `    ``/* Reverse and Add Function */``    ``void` `ReverseandAdd(``long` `num)``    ``{``        ``long` `rev_num = ``0``;``        ``while` `(num <= 4294967295l)``        ``{``            ``// Reversing the digits of the number``            ``rev_num = reversDigits(num);`` ` `            ``// Adding the reversed number with the original``            ``num = num + rev_num;`` ` `            ``// Checking whether the number is palindrome or not``            ``if``(isPalindrome(num))``            ``{``                ``System.out.println(num);``                ``break``;``            ``}``            ``else` `if` `(num > 4294967295l)``            ``{``                ``System.out.println(``"No palindrome exist"``);``            ``}``        ``}``    ``}``     ` `    ``// Main method``    ``public` `static` `void` `main(String[] args) ``    ``{``        ``ReverseAdd ob = ``new` `ReverseAdd();``        ``ob.ReverseandAdd(195l);``        ``ob.ReverseandAdd(265l);``         ` `    ``}``}`

## Python

 `#Python Program to implement reverse and add function`` ` `# Iterative function to reverse digits of num``def` `reversDigits(num):``    ``rev_num``=``0``    ``while` `(num > ``0``):``        ``rev_num ``=` `rev_num``*``10` `+` `num``%``10``        ``num ``=` `num``/``10``    ``return` `rev_num`` ` `# Function to check whether the number is palindrome or not``def` `isPalindrome(num):``    ``return` `(reversDigits(num) ``=``=` `num)`` ` `# Reverse and Add Function``def` `ReverseandAdd(num):``    ``rev_num ``=` `0``    ``while` `(num <``=` `4294967295``):``        ``# Reversing the digits of the number``        ``rev_num ``=` `reversDigits(num)`` ` `        ``# Adding the reversed number with the original``        ``num ``=` `num ``+` `rev_num`` ` `        ``# Checking whether the number is palindrome or not``        ``if``(isPalindrome(num)):``            ``print` `num``            ``break``        ``else``:``            ``if` `(num > ``4294967295``):``                ``print` `"No palindrome exist"`` ` `# Driver Code``ReverseandAdd(``195``)``ReverseandAdd(``265``)`

## C#

 `// C# Program to implement reverse and add function``using` `System;`` ` `class` `GFG ``{``    ``/* Iterative function to reverse digits of num*/``    ``static` `long` `reversDigits(``long` `num)``    ``{``        ``long` `rev_num = 0;``        ``while` `(num > 0)``        ``{``            ``rev_num = rev_num * 10 + num % 10;``            ``num = num / 10;``        ``}``        ``return` `rev_num;``    ``}`` ` `    ``/* Function to check whether he number is``        ``palindrome or not */``    ``static` `bool` `isPalindrome(``long` `num)``    ``{``        ``return` `(reversDigits(num) == num);``    ``}`` ` `    ``/* Reverse and Add Function */``    ``static` `void` `ReverseandAdd(``long` `num)``    ``{``        ``long` `rev_num = 0;``        ``while` `(num <= 4294967295)``        ``{``            ``// Reversing the digits of the number``            ``rev_num = reversDigits(num);`` ` `            ``// Adding the reversed number with the original``            ``num = num + rev_num;`` ` `            ``// Checking whether the number is palindrome or not``            ``if``(isPalindrome(num))``            ``{``                ``Console.WriteLine(num);``                ``break``;``            ``}``            ``else` `if` `(num > 4294967295)``            ``{``                ``Console.WriteLine(``"No palindrome exist"``);``            ``}``        ``}``    ``}``     ` `    ``// Driver code``    ``public` `static` `void` `Main() ``    ``{``        ``ReverseandAdd(195);``        ``ReverseandAdd(265);``    ``}``}`` ` `// This code is contributed by chandan_jnu`

## PHP

 ` 0)``    ``{``        ``\$rev_num` `= ``\$rev_num` `* 10 + ``\$num` `% 10;``        ``\$num` `= (int)(``\$num` `/ 10);``    ``}``    ``return` `\$rev_num``;``}`` ` `/* Function to check whether he number``   ``is palindrome or not */``function` `isPalindrome(``\$num``)``{``    ``return` `(reversDigits(``\$num``) == ``\$num``);``}`` ` `/* Reverse and Add Function */``function` `ReverseandAdd(``\$num``)``{``     ``\$rev_num` `= 0;``    ``while` `(``\$num` `<= 4294967295)``    ``{``        ``// Reversing the digits of the number``        ``\$rev_num` `= reversDigits(``\$num``);`` ` `        ``// Adding the reversed number with``        ``// the original``        ``\$num` `= ``\$num` `+ ``\$rev_num``;`` ` `        ``// Checking whether the number is``        ``// palindrome or not``        ``if` `(isPalindrome(``\$num``))``        ``{``            ``print``(``\$num` `. ``"\n"``);``            ``break``;``        ``}``        ``else` `if` `(``\$num` `> 4294967295)``        ``{``            ``print``(``"No palindrome exist"``);``        ``}``    ``}``}`` ` `// Driver Code``ReverseandAdd(195);``ReverseandAdd(265);`` ` `// This code is contributed by chandan_jnu``?>`

Output:

```9339
45254
```

This article is contributed by Rahul Agrawal. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

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