externcrate reachability_solver;usereachability_solver::solve;fnmain(){// This example shows that even if the node `2` is initial,
// it must reach a terminal node to be included in the solution.
//// 2
// |
// 4--5--6
// | |
// 7 9
// | |
// 10-11-12
//println!("{:?}",solve(vec![[2,5],[5,6],[6,9],[9,12],[12,11],[11,10],[10,7],[7,4],[4,5]]))}