Kata

A palindrome is a word, phrase, number, or other sequence of characters which reads the same backward as forward. Examples of numerical palindromes are:

2332
110011
54322345

For this kata, single digit numbers will not be considered numerical palindromes.

For a given number num, write a function to test if the number contains a numerical palindrome or not and return a boolean (true if it does and false if does not). Return "Not valid" if the input is not an integer or is less than 0.

Note: Palindromes should be found without permutating num.

palindrome(5) => false
palindrome(1221) => true
palindrome(141221001) => true
palindrome(1215) => true 
palindrome(1294) => false 
palindrome("109982") => "Not valid"

In Haskell, this returns a Maybe Bool, with Nothing for an input less than zero.

Other Kata in this Series:

Numerical Palindrome #1
Numerical Palindrome #1.5
Numerical Palindrome #2
Numerical Palindrome #3
Numerical Palindrome #3.5
Numerical Palindrome #4
Numerical Palindrome #5