Project Euler 55 - Lychrel Numbers

Official link:

Thought Process

I have 2 functions

  1. ispalindrome(x)

    • Pretty self explanatory function, returns True if x is a palindrome, returns False if it is not

  2. compute(limit)

    • This function will find all lychrel numbers less than limit by finding all the non-lychrel-numbers

    • It's a brute force way, I check all numbers from 1 to limit while updating the number

      1. I do a quick check to see if the number I am currently checking is a palindrome, if it is I move it one step forward and add its reverse to it

    • Then I have a for loop, which simply adds the reverse to a number 50 times, until it is a palindrome in which case I add 1 to the count of non-lychrel-numbers and break the loop.

    • After everything is done I return (limit - non-lychrel-numbers)

Interactive Code

Input an integer (yourinput)

Code will output the number of lychrel numbers < yourinput