Function multi_commodity_flow 

pub fn multi_commodity_flow(
    n: usize,
    edge_caps: &[(usize, usize, f64)],
    commodities: &[(usize, usize, f64)],
) -> Result<MultiCommodityFlowResult>

Multi-commodity flow using LP relaxation via iterative proportional scaling.

Approximates the multi-commodity flow problem where multiple commodities share network capacity. Uses a simple iterative approach.

Arguments

• n - Number of nodes
• edge_caps - Edges as (from, to, capacity)
• commodities - List of (source, sink, demand) for each commodity