Compute pipeline order from dependencies

You are given a set of pipelines and a list of directed dependency pairs (A, B) meaning pipeline A depends on pipeline B and therefore B must run before A. Return one valid execution order that satisfies all dependencies, or report that no such order exists if there is a cycle. For example, for pipelines [P1, P2, P3] with dependencies [(P1, P 2), (P3, P 2)], produce a valid order such as [P2, P1, P3]. Describe the algorithm, data structures used, and time/space complexity. Provide code using both a DFS-based topological sort and Kahn’s algorithm, and discuss how you would handle tie-breaking among independent pipelines and very large graphs.