[saurik]

Yes, I know that topological sort is O(|V| + |E|). What I am claiming is that the problem of buying building materials in an optimal order isn't topological sort: there are numerous topological orders of a graph, but some will be much much slower than others to build at your construction site. To determine which of the many possible orders is the fastest one, you have to take into account how long various tasks will take and how many workers you have available for those tasks. When you get some materials, that unlocks certain parts of the gantt chart of what sounds like Job Shop Scheduling. To me, this is the same form of complaint as pointing out that Traveling Salesman isn't Topological Sort.