Graph: A directed graph G(V,E)
Supply & Target: supply(S) and target(T). We want to send from supply to target, there can be infinite supply avaliable.
Capacity: Each edge has some capacity c(x,y)
Flow: The actual amount we send is called flow f(x,y). And it cannot exceed capacity. 0 ≤ c(x,y) ≤ f(x,y).
Flow Conservation: For each node that is not supply or target, the incoming flow is equal to outgoing flow.
Value: The value |f| of a flow f is defined as:
|f| = ∑v in V f(s,v) - ∑v in V f(v,s)
That is the total flow out of source - the total flow into source
It is trivial that we want to minimize the flow going back to source.
Output: Compute flow on each edge such that we have maximum flow coming to target.
11 + 1 = 12
8 + 4 = 11 + 1
12 + 7 = 15 + 4
11 = 7 + 4
4 + 15 = 19