Timetable Layout.md

Timetable layout is a hard problem to solve for all cases. Here’s an approach which will not generalize to all routes, but works often enough to be useful (link). In short, build a directed graph of all adjacent stop pairs (edges) made by trips in the timetable and topologically sort it to get the “header row”, then layout the stop times accordingly. A fully generalized approach requires finding an approximation of the shortest common supersequence of the set of stopping patterns—which is definitely non-trivial to do really well.