Function reachability_solver::etch::cardinality

pub fn cardinality(x: &[[usize; 2]]) -> usize

Measures the cardinality of a maze by removing initial nodes repeatedly, until there are no edges left.

The cardinality is the same whether initial or terminal nodes are removed.

The cardinality of an empty maze is zero.

The cardinality measures the maximum number of steps required to reach any goal, plus one.