1 // Part 3 about finding a single tour using the Warnsdorf Rule

     2 //=============================================================

     3 

     4 // copy any function you need from files knight1.scala and

     5 // knight2.scala

     6 

     7 object CW7c {

     8 

     9 type Pos = (Int, Int)    // a position on a chessboard 

    10 type Path = List[Pos]    // a path...a list of positions

    11 

    12 //(3a) Complete the function that calculates a list of onward

    13 //     moves like in (1b) but orders them according to Warnsdorf’s 

    14 //     rule. That means moves with the fewest legal onward moves 

    15 //     should come first.

    16 

    17 //def ordered_moves(dim: Int, path: Path, x: Pos) : List[Pos] = ..

    18 

    19 

    20 //(3b) Complete the function that searches for a single *closed* 

    21 //     tour using the ordered moves function.

    22 

    23 //def first_closed_tour_heuristic(dim: Int, path: Path) : Option[Path] = ...

    24 

    25 

    26 //(3c) Same as (3b) but searches for *non-closed* tours. However, 

    27 //     you have to be careful to write a tail-recursive version as this 

    28 //     function will be called with dimensions of up to 40 * 40.

    29 

    30 //def first_tour_heuristic(dim: Int, path: Path) : Option[Path] = ...

    31 

    32 

    33 }