Slightly improved MapReduce sunflowers

Slightly improved MapReduce sunflowers

I just realized that in the post I promised to share a new version of map-reduce sunflowers with a small improvement for watering cells with tall sunflowers.

There are no 10 fire flags, but 4 flags is good enough for me, I really appreciate it.

So, small improvement: the whole code

Exact line - we check if the sunflower is a tallest possible one, and if it is, we provide it with water.

Different logic for coordinates: for each height we store a list of points

A little bit different merge stage.