Day 2: Red-Nosed Reports

For the last point, it isn't needed since the differences between elements should be all positive or all negative for the report to be safe. This is tested with the combination of negate and gradual.

I am also enjoying these Haskell solutions. I'm still learning the language, so it's been cool to compare my solution with these and grow my understanding of Haskell.

<$> is just fmap as an infix operator.

>>> fmap (+1) [1,2,3]
[2,3,4]
>>> (+1) <\$> [1,2,3]
[2,3,4]

Thanks! The other two posters already answered your questions, I think :)

Haskell makes it really easy to build complex operations out of simple functional building blocks, skipping a lot of boilerplate needed in some other languages. I find the compactness easier to read, but I realize that not everyone would agree.

BTW, I'm a relative Haskell newbie. I'm sure more experienced folks could come up with even more interesting solutions!