Negative cycle-canceling

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Abstract view

Algorithmic problem: Min-cost flow problem

Type of algorithm: loop

Invariant: The flow is feasible.

Variant: The cost of the flow decreases.

Definition:' A cycle is negative if the sum of the cost values on all of its arcs is negative.

Break condition: There is no more negative cycle in the residual network.

Induction basis

Abstract view: Start with an arbitrary feasible flow, for example, the zero flow.

Induction step

Abstract view:

  1. Find a cycle of negative cost in the residual network.
  2. Augme