Download Speed - Edge Cases

Edge cases to handle:

$1.$ Source equals sink: maximum flow is infinity (or undefined). Problem statements usually avoid this.

$2.$ No path from source to sink: maximum flow is $0$.

$3.$ Single edge: maximum flow is the edge capacity.

$4.$ Multiple edges between same nodes: sum their capacities or treat separately.

Always check if $n = 1$ (source equals sink). If the graph is disconnected, BFS returns immediately with flow $0$.