# Find all palindrome numbers of given digits

Given an integer D, the task is to find all the D-digit palindrome numbers.

Examples:

Input: D = 1
Output: 1 2 3 4 5 6 7 8 9

Input: D = 2
Output: 11 22 33 44 55 66 77 88 99

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: Numbers with D-digits start from 10(D – 1) to 10D – 1. So, start checking every number from this interval whether it is palindrome or not.

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach ` `#include ` `using` `namespace` `std; ` ` `  `// Function to return the ` `// reverse of num ` `int` `reverse(``int` `num) ` `{ ` `    ``int` `rev = 0; ` `    ``while` `(num > 0) { ` `        ``rev = rev * 10 + num % 10; ` `        ``num = num / 10; ` `    ``} ` `    ``return` `rev; ` `} ` ` `  `// Function that returns true ` `// if num is palindrome ` `bool` `isPalindrome(``int` `num) ` `{ ` ` `  `    ``// If the number is equal to the ` `    ``// reverse of it then it ` `    ``// is a palindrome ` `    ``if` `(num == reverse(num)) ` `        ``return` `true``; ` ` `  `    ``return` `false``; ` `} ` ` `  `// Function to print all the ` `// d-digit palindrome numbers ` `void` `printPalindromes(``int` `d) ` `{ ` `    ``if` `(d <= 0) ` `        ``return``; ` ` `  `    ``// Smallest and the largest d-digit numbers ` `    ``int` `smallest = ``pow``(10, d - 1); ` `    ``int` `largest = ``pow``(10, d) - 1; ` ` `  `    ``// Starting from the smallest d-digit ` `    ``// number till the largest ` `    ``for` `(``int` `i = smallest; ` `         ``i <= largest; i++) { ` ` `  `        ``// If the current number ` `        ``// is palindrome ` `        ``if` `(isPalindrome(i)) ` `            ``cout << i << ``" "``; ` `    ``} ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``int` `d = 2; ` ` `  `    ``printPalindromes(d); ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java implementation of the approach  ` `class` `GFG  ` `{ ` `     `  `    ``// Function to return the  ` `    ``// reverse of num  ` `    ``static` `int` `reverse(``int` `num)  ` `    ``{  ` `        ``int` `rev = ``0``;  ` `        ``while` `(num > ``0``)  ` `        ``{  ` `            ``rev = rev * ``10` `+ num % ``10``;  ` `            ``num = num / ``10``;  ` `        ``}  ` `        ``return` `rev;  ` `    ``}  ` `     `  `    ``// Function that returns true  ` `    ``// if num is palindrome  ` `    ``static` `boolean` `isPalindrome(``int` `num)  ` `    ``{  ` `     `  `        ``// If the number is equal to the  ` `        ``// reverse of it then it  ` `        ``// is a palindrome  ` `        ``if` `(num == reverse(num))  ` `            ``return` `true``;  ` `     `  `        ``return` `false``;  ` `    ``}  ` `     `  `    ``// Function to print all the  ` `    ``// d-digit palindrome numbers  ` `    ``static` `void` `printPalindromes(``int` `d)  ` `    ``{  ` `        ``if` `(d <= ``0``)  ` `            ``return``;  ` `     `  `        ``// Smallest and the largest d-digit numbers  ` `        ``int` `smallest = (``int``)Math.pow(``10``, d - ``1``);  ` `        ``int` `largest = (``int``)Math.pow(``10``, d) - ``1``;  ` `     `  `        ``// Starting from the smallest d-digit  ` `        ``// number till the largest  ` `        ``for` `(``int` `i = smallest; i <= largest; i++) ` `        ``{  ` ` `  `            ``// If the current number  ` `            ``// is palindrome  ` `            ``if` `(isPalindrome(i))  ` `                ``System.out.print(i + ``" "``);  ` `        ``}  ` `    ``}  ` `     `  `    ``// Driver code  ` `    ``public` `static` `void` `main (String[] args) ` `    ``{  ` `        ``int` `d = ``2``;  ` `     `  `        ``printPalindromes(d);  ` `    ``}  ` `} ` ` `  `// This code is contributed by AnkitRai01 `

## Python3

 `# Python implementation of the approach ` ` `  `# Function to return the ` `# reverse of num ` `def` `reverse(num): ` `    ``rev ``=` `0``; ` `    ``while` `(num > ``0``): ` `        ``rev ``=` `rev ``*` `10` `+` `num ``%` `10``; ` `        ``num ``=` `num ``/``/` `10``; ` ` `  `    ``return` `rev; ` ` `  `# Function that returns true ` `# if num is palindrome ` `def` `isPalindrome(num):  ` `    ``# If the number is equal to the ` `    ``# reverse of it then it ` `    ``# is a palindrome ` `    ``if` `(num ``=``=` `reverse(num)): ` `        ``return` `True``; ` ` `  `    ``return` `False``; ` ` `  `# Function to prall the ` `# d-digit palindrome numbers ` `def` `printPalindromes(d): ` ` `  `    ``if` `(d <``=` `0``): ` `        ``return``; ` ` `  `    ``# Smallest and the largest d-digit numbers ` `    ``smallest ``=` `pow``(``10``, d ``-` `1``); ` `    ``largest ``=` `pow``(``10``, d) ``-` `1``; ` ` `  `    ``# Starting from the smallest d-digit ` `    ``# number till the largest ` `    ``for` `i ``in` `range``(smallest, largest ``+` `1``): ` ` `  `        ``# If the current number ` `        ``# is palindrome ` `        ``if` `(isPalindrome(i)): ` `            ``print``(i, end ``=` `" "``); ` ` `  `# Driver code ` `d ``=` `2``; ` ` `  `printPalindromes(d); ` ` `  `# This code is contributed by 29AjayKumar `

## C#

 `// C# implementation of the approach ` `using` `System; ` `     `  `class` `GFG  ` `{ ` `     `  `    ``// Function to return the  ` `    ``// reverse of num  ` `    ``static` `int` `reverse(``int` `num)  ` `    ``{  ` `        ``int` `rev = 0;  ` `        ``while` `(num > 0)  ` `        ``{  ` `            ``rev = rev * 10 + num % 10;  ` `            ``num = num / 10;  ` `        ``}  ` `        ``return` `rev;  ` `    ``}  ` `     `  `    ``// Function that returns true  ` `    ``// if num is palindrome  ` `    ``static` `bool` `isPalindrome(``int` `num)  ` `    ``{  ` `     `  `        ``// If the number is equal to the  ` `        ``// reverse of it then it  ` `        ``// is a palindrome  ` `        ``if` `(num == reverse(num))  ` `            ``return` `true``;  ` `     `  `        ``return` `false``;  ` `    ``}  ` `     `  `    ``// Function to print all the  ` `    ``// d-digit palindrome numbers  ` `    ``static` `void` `printPalindromes(``int` `d)  ` `    ``{  ` `        ``if` `(d <= 0)  ` `            ``return``;  ` `     `  `        ``// Smallest and the largest d-digit numbers  ` `        ``int` `smallest = (``int``)Math.Pow(10, d - 1);  ` `        ``int` `largest = (``int``)Math.Pow(10, d) - 1;  ` `     `  `        ``// Starting from the smallest d-digit  ` `        ``// number till the largest  ` `        ``for` `(``int` `i = smallest; i <= largest; i++) ` `        ``{  ` ` `  `            ``// If the current number  ` `            ``// is palindrome  ` `            ``if` `(isPalindrome(i))  ` `                ``Console.Write(i + ``" "``);  ` `        ``}  ` `    ``}  ` `     `  `    ``// Driver code  ` `    ``public` `static` `void` `Main (String[] args) ` `    ``{  ` `        ``int` `d = 2;  ` `     `  `        ``printPalindromes(d);  ` `    ``}  ` `} ` ` `  `// This code is contributed by Rajput-Ji `

Output:

```11 22 33 44 55 66 77 88 99
```

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