When the user wants to solve flow problems on a network - max-flow/min-cut, min-cost flow, multicommodity flow, or shortest paths via Dijkstra, Bellman-Ford, and label-correcting methods - using networkx, gurobipy, or specialized algorithms, including when total unimodularity makes LP solutions integral for free. Also use when the user mentions "network flow," "min-cost flow," "max flow," "multicommodity," "shortest path," "flow conservation," or when the constraints have flow-balance structure on a graph. For one-to-one matching, see assignment-problems; for duality and sensitivity background, see linear-programming-fundamentals.
