# Max Common Array Slice with Ruby

Question: We need a program which takes a comma delimited array of numbers from STDIN and will output the maximum slice of the array which contains **no more than two different numbers**. Your result should be written to STDOUT.

**Example 1:**

[1, 1, 1, 2, 2, 2, 1, 1, 2, 2, 6, 2, 1, 8] = 10 because the array slice of (0, 9) is the largest slice of the array with no more than two different numbers.

**Example 2:**

[53, 800, 0, 0, 0, 356, 8988, 1, 1] = 4 because the slice of (1, 4) is the largest slice of the array with no more than two different numbers. The slice (2, 5) would also be valid and would still give a result of 4.

'Max common array slice' (also known as Maximum sub-array problem) is a classical programming test question requiring some knowledge of O(n^{2}) or O(n^{3}). It is often asked in technical interviews in two different ways; a) maximum sum of array elements with no more than two different numbers, b) maximum length of array elements with no more than two different numbers. You can see more about Max Common Array Slice on Codility and Wikipedia.

**Date:**14-06-2017