Function edge_disjoint_paths 

pub fn edge_disjoint_paths(
    graph: &Graph,
    source: VertexId,
    target: VertexId,
) -> IgraphResult<i64>

Maximum number of pairwise edge-disjoint paths from source to target.

Counterpart of igraph_edge_disjoint_paths in references/igraph/src/flow/flow.c:2326. By Menger’s theorem (1927) this equals the s-t edge connectivity (and, on unit capacities, the s-t maximum flow); see st_edge_connectivity for the connectivity-flavoured spelling.

Arguments

• graph — input graph (directed or undirected).
• source — source vertex id (0 ≤ source < vcount()).
• target — sink vertex id (0 ≤ target < vcount(), target != source).

Returns

The maximum number of edge-disjoint source → target paths as i64. Returns 0 when no source → target path exists.

Errors

Same as max_flow_value:

• IgraphError::VertexOutOfRange if source or target is outside [0, vcount()).
• IgraphError::InvalidArgument if source == target. (igraph C returns IGRAPH_UNIMPLEMENTED for this case; we use InvalidArgument for parity with the rest of our flow module.)
• IgraphError::Internal if the unit-capacity max-flow value is not representable as i64 (unreachable in practice).

Examples

use rust_igraph::{Graph, edge_disjoint_paths};

// Two parallel unit-cap paths 0→1→3 and 0→2→3 → 2 edge-disjoint paths.
let mut g = Graph::new(4, true).unwrap();
g.add_edge(0, 1).unwrap();
g.add_edge(1, 3).unwrap();
g.add_edge(0, 2).unwrap();
g.add_edge(2, 3).unwrap();
assert_eq!(edge_disjoint_paths(&g, 0, 3).unwrap(), 2);