When should I use topological sorting?

What is topological sorting and when should I use it?

Topological sorting is an ordering of the vertices in a directed acyclic graph (DAG) such that for every directed edge u -> v, vertex u comes before v. You should use it when you need to schedule tasks, resolve dependencies, or organize data in a way that respects certain constraints.

Can you give me an example of where topological sorting is applied?

Sure! A common example is in task scheduling, like when you have a set of tasks that depend on each other. For instance, if task A must be completed before task B, topological sorting helps determine the order in which to perform these tasks.

Are there any algorithms specifically for topological sorting?

Yes, there are several algorithms for topological sorting, including Kahn's algorithm and depth-first search (DFS) based approach. Both can efficiently produce a topological order for a given DAG.

What happens if I try to topologically sort a graph with cycles?

If a graph has cycles, topological sorting is not possible because there is no way to order the vertices without violating the dependency constraints. You would need to detect and remove cycles first.