SRM 572, d2 250 - NextOrPrev editorial (WIP)

And the editorial now has explanations for the easier problems of SRM 572. Language corrections and tweaks not done yet.

Problem statement

Link to editorial explanation.

This problem was a bit harder than usual for division 2 Medium. I mean, it is not exactly easy to figure out greedy works. And when you do, you might miss one of the conditions necessary for the case to be solvable and fail system tests ( Like what happened to me when I tried it in the practice room.).

It was fun making pictures for this problem. Today I was thinking about how natural using Inkspace became to me. Truly, when you do something plenty of times you start getting good at it. I have been writing editorials for years now and I remember not knowing as many Inkscape tricks as I do know.

The whole Inkscape thing became such a fluid thing that on Wednesday, when I was asking to make flow charts for a college assignment (Really? Flow charts? What are we, eight?). I preferred to grab Inkscape than do it by hand or with a diagram designer.

I am still horribly clueless about the division 1 hard. Which is a much, much, much, much harder version of this problem. Letters are allowed multiple times, and it is possible to move from 'z' to 'a' and from 'a' to 'z'.