1
Initial flow network:
graph LR; s-->|"(8)"|a; s-->|"(3)"|b; b-->|"(2)"|a; b-->|"(4)"|d; a-->|"(7)"|p; p-->|"(5)"|d; p-->|"(3)"|t; d-->|"(5)"|t; b-->|"(2)"|c; c-->|"(1)"|d; c-->|"(3)"|h; h-->|"(1)"|d; h-->|"(3)"|t;
The residual network is the same.
s=>a=>p=>d=>t, bottleneck 5
New flow network:
graph LR; s-->|"5(8)"|a; s-->|"(3)"|b; b-->|"(2)"|a; b-->|"(4)"|d; a-->|"5(7)"|p; p-->|"5(5)"|d; p-->|"(3)"|t; d-->|"5(5)"|t; b-->|"(2)"|c; c-->|"(1)"|d; c-->|"(3)"|h; h-->|"(1)"|d; h-->|"(3)"|t;
Residual network:
graph LR; s-->|"(3)"|a; a-->|"(5)"|s; s-->|"(3)"|b; b-->|"(2)"|a; b-->|"(4)"|d; a-->|"(2)"|p; p-->|"(5)"|a; d-->|"(5)"|p; p-->|"(3)"|t; t-->|"(5)"|d; b-->|"(2)"|c; c-->|"(1)"|d; c-->|"(3)"|h; h-->|"(1)"|d; h-->|"(3)"|t;
s=>b=>d=>p=>t, bottleneck 3
New flow network:
graph LR; s-->|"5(8)"|a; s-->|"3(3)"|b; b-->|"(2)"|a; b-->|"3(4)"|d; a-->|"5(7)"|p; p-->|"2(5)"|d; p-->|"3(3)"|t; d-->|"5(5)"|t; b-->|"(2)"|c; c-->|"(1)"|d; c-->|"(3)"|h; h-->|"(1)"|d; h-->|"(3)"|t;
Residual network:
graph LR; s-->|"(3)"|a; a-->|"(5)"|s; b-->|"(3)"|s; b-->|"(2)"|a; b-->|"(1)"|d; d-->|"(3)"|b; p-->|"(5)"|a; a-->|"(2)"|p; d-->|"(2)"|p; p-->|"(3)"|d; t-->|"(3)"|p; t-->|"(5)"|d; b-->|"(2)"|c; c-->|"(1)"|d; c-->|"(3)"|h; h-->|"(1)"|d; h-->|"(3)"|t;
(might be wrong)
Final answer:
graph LR; s-->|"7(8)"|a; s-->|"3(3)"|b; b-->|"(2)"|a; b-->|"1(4)"|d; a-->|"7(7)"|p; p-->|"4(5)"|d; p-->|"3(3)"|t; d-->|"5(5)"|t; b-->|"2(2)"|c; c-->|"(1)"|d; c-->|"2(3)"|h; h-->|"(1)"|d; h-->|"2(3)"|t;
2
3
with net
4
5
6
We know there are two minimum cuts. To increase max. flow by , we must increase the capacity on an edge from each boundary crossing the cuts.