Function split_edges_connected 

pub fn split_edges_connected(
    graph: &Graph,
    test_fraction: f64,
    seed: u64,
) -> IgraphResult<EdgeSplit>

Split edges ensuring the training graph remains connected.

Like split_edges but guarantees that removing the test edges does not disconnect the graph. Edges whose removal would create a bridge (disconnection) are kept in training. If maintaining connectivity limits the test set size, fewer edges than requested may end up in test.

Examples

use rust_igraph::{Graph, split_edges_connected};

// Cycle: every edge can be removed without disconnecting
let g = Graph::from_edges(
    &[(0,1),(1,2),(2,3),(3,0)], false, Some(4)
).unwrap();

let split = split_edges_connected(&g, 0.5, 42).unwrap();
assert_eq!(split.train.len() + split.test.len(), 4);
// Test set has at most 2 edges (50%)
assert!(split.test.len() <= 2);