// Part 3 about finding a single tour using the Warnsdorf Rule
//=============================================================
// copy any function you need from files knight1.scala and
// knight2.scala
type Pos = (Int, Int) // a position on a chessboard
type Path = List[Pos] // a path...a list of positions
//(3a) Complete the function that calculates a list of onward
// moves like in (1b) but orders them according to the Warnsdorf’s
// rule. That means moves with the fewest legal onward moves
// should come first.
def ordered_moves(dim: Int, path: Path, x: Pos): List[Pos] = ..
//(3b) Complete the function that searches for a single *closed*
// tour using the ordered moves function.
def first_closed_tour_heuristic(dim: Int, path: Path): Option[Path] = ...
//(3c) Same as (3b) but searches for *open* tours.
def first_tour_heuristic(dim: Int, path: Path): Option[Path] = ...