JavaExercism/exercises/palindrome-products

Palindrome Products

Detect palindrome products in a given range.

A palindromic number is a number that remains the same when its digits are reversed. For example, 121 is a palindromic number but 112 is not.

Given the definition of a palindromic number, we define a palindrome product to be the product c, such that a * b = c, where c is a palindromic number and a and b are integers (possibly, but not necessarily palindromic numbers).

For example, the palindromic number 9009 can be written as the palindrome product: 91 * 99 = 9009.

It's possible (and indeed common) for a palindrome product to be the product of multiple combinations of numbers. For example, the palindrome product 9 has the factors (1, 9), (3, 3), and (9, 1).

Write a program that given a range of integers, returns the smallest and largest palindromic product within that range, along with all of it's factors.

Example 1

Given the range [1, 9] (both inclusive)...

The smallest product is 1. It's factors are (1, 1). The largest product is 9. It's factors are (1, 9), (3, 3), and (9, 1).

Example 2

Given the range [10, 99] (both inclusive)...

The smallest palindrome product is 121. It's factors are (11, 11). The largest palindrome product is 9009. It's factors are (91, 99) and (99, 91).

To run the tests:

$ gradle test

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Source

Problem 4 at Project Euler http://projecteuler.net/problem=4

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