Minimum Cut Problem

This is an alternate formulation to the Max Flow Problem. Theorem: Minimum Cut = Max Flow
 * We want to remove some edges from the graph such that after removing the edges, there is no path from s to t.
 * The cost of removing e is equal to c(e).
 * The minimum cut problem is to find a cut with minimum total cost.

Since we know the max flow, we can use the Residual Graph to find the min cut.

Algorithm
Steps:
 * 1) Mark all nodes reachable from S. Call this set of reachable nodes A.
 * 2) Now separate these nodes from the others. Cut edges going from A to V - A
 * 3) Now look at the original graph and find the cut.