Somehow I created this graph which seems to violate one of the properties that the value of flow is upper bounded by the capacity of min cut.
Here's the graph:
Max flow that the algorithm finds is 7. (sending 3 on s-a-c-t, 3 on s-b-t and 1 on s-a-t)
While the min-cut in the graph is {s,b} , {a,c,t} with capacity 5.
I'm not sure where I'm going wrong in this. Can someone please correct this?
The value of a cut is the sum of the capacities of the edges that are "cut".
In the case with cutting the graph into {s,b}
and {a,c,t}
, the edges are s-a
, b-t
, (and you can count a-b
if you want), which means the value is 8 (11 if you count a-b
), not 5.
As far as I can tell, the min cut would include the edges a-t
, b-t
, and c-t
, which has a value of 7, which is consistent with Ford-Fulkerson.