The following matrix gives the capacities of the pipes in a system.
\begin{array}{c|c|c|c|c|c|c|c}
To & & S & T & A & B & C & D
From & & & & & & &
\hline
S & & -- & -- & 16 & 26 & -- & --
T & & -- & -- & -- & -- & -- & --
A & & -- & -- & -- & -- & 13 & 5
B & & -- & 16 & -- & -- & -- & 11
C & & -- & 11 & -- & -- & -- & --
D & & -- & 11 & -- & -- & -- & --
\end{array}
- Represent this information as a digraph. [3 marks]
- Find the minimum cut, expressing it in the form \(\{\) \(\}|\{\) \(\}\), and state its value. [2 marks]
- Starting from having no flow in the system, use the labelling procedure to find a maximal flow through the system. You should list each flow-augmenting route you use, together with its flow. [5 marks]
- Explain how you know that this flow is maximal. [1 mark]
[11 marks]