Find the length of the longest sub-sequence of two distinct numbers whose difference is 1. A sub-sequence can be made by deleting any numbers in between.
almost_uniform([1, 3, 2, 2, 5, 2, 3, 7]) ➞ 5
# [3, 2, 2, 2, 3]
almost_uniform([1, 2, 3, 4]) ➞ 2
# [1, 2] or [2, 3] or [3, 4]
almost_uniform([1, 1, 1, 1]) ➞ 0
# There is no sub-sequence of two distinct numbers.
N/A