1 

     2 

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

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

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

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

     4 

     5 

     5 def add_pair_urban(x: Pos)(y: Pos): Pos = 

     6 def add_pair_urban(x: Pos)(y: Pos): Pos = 

    20   case x::Nil => true

    21   case x::Nil => true

    21   case x::y::p => if (legal_moves_urban(dim, p, y).contains(x)) correct_urban(dim)(y::p) else false

    22   case x::y::p => if (legal_moves_urban(dim, p, y).contains(x)) correct_urban(dim)(y::p) else false

    22 }

    23 }

    23 

    24 

    24 

    25 

    25 

    30 

    26 val ts_urban = enum_tours(5, List((0, 2)))

    31 val ts_urban = enum_tours(5, List((0, 2)))

    27 assert(ts_urban.map(correct_urban(5)).forall(_ == true) == true)

    32 assert(ts_urban.map(correct_urban(5)).forall(_ == true) == true)

    28 assert(ts_urban.length == 56)  

    33 assert(ts_urban.length == 56)