--- a/testing2/knight1.scala Thu Nov 15 14:23:55 2018 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,133 +0,0 @@
-
-// Part 1 about finding and counting Knight's tours
-//==================================================
-
-object CW7a extends App{
-
-type Pos = (Int, Int) // a position on a chessboard
-type Path = List[Pos] // a path...a list of positions
-
-//(1a) Complete the function that tests whether the position
-// is inside the board and not yet element in the path.
-
-//def is_legal(dim: Int, path: Path)(x: Pos) : Boolean = ...
-
-def is_legal(dim: Int, path: Path)(x: Pos) : Boolean = {
-
-// if ((x._1<dim && x._2<dim) && (x._1>0 || x._2>0)) false else !path.contains(x)
-
- if (x._1 < 0 || x._2 < 0) false
- else if (x._1 < dim && x._2 < dim && !path.contains(x)) true
- else false
-
-
-}
-
-
-
-def legal_moves(dim: Int, path: Path, x: Pos) : List[Pos] = {
-
- val allPossibleMoves = List((x._1+1, x._2+2), (x._1+2, x._2+1), (x._1+2, x._2-1), (x._1+1, x._2-2), (x._1-1, x._2-2), (x._1-2, x._2-1), (x._1-2, x._2+1), (x._1-1, x._2+2));
-
- //val finalList = allPossibleMoves.filter((a=>a._1<dim && a._2<dim && x._1 >= 0 && a._2 >= 0));
-
- val finalList = for(pos<-allPossibleMoves if(is_legal(dim,path)(pos))) yield pos;
-
- // println("Space in board: " + dim*dim + " for dim: " + dim)
-
-
- finalList.toList;
-
-
-}
-
-println(legal_moves(8, Nil, (2,2)))
-println(legal_moves(8, Nil, (7,7)))
-println(legal_moves(8, List((4,1), (1,0)), (2,2)))
-println(legal_moves(8, List((6,6)), (7,7)))
-println(legal_moves(1, Nil, (0,0)))
-println(legal_moves(2, Nil, (0,0)))
-println(legal_moves(3, Nil, (0,0)))
-
-println("=================================================================================")
-println("================================Comparision output===============================")
-println("=================================================================================")
-
-println(legal_moves(8, Nil, (2,2)) == List((3,4), (4,3), (4,1), (3,0), (1,0), (0,1), (0,3), (1,4)))
-println(legal_moves(8, Nil, (7,7)) == List((6,5), (5,6)))
-println(legal_moves(8, List((4,1), (1,0)), (2,2)) == List((3,4), (4,3), (3,0), (0,1), (0,3), (1,4)))
-println(legal_moves(8, List((6,6)), (7,7)) == List((6,5), (5,6)))
-println(legal_moves(1, Nil, (0,0)) == Nil)
-println(legal_moves(2, Nil, (0,0)) == Nil)
-println(legal_moves(3, Nil, (0,0)) == List((1,2), (2,1)))
-
-
-def count_tours(dim: Int, path: Path) : Int = {
-
- val allMovesFromCurrentPosition = legal_moves(dim, path, path.head);
-
- if (path.length == dim*dim) 1 else {
-
- if (allMovesFromCurrentPosition.size == 0 ) 0 else {
-
- allMovesFromCurrentPosition.map( element => count_tours(dim, element::path)).sum
-
-
- }
-
- }
-
-}
-
-
-
-println ( count_tours(5, List((0,0))) )
-
-def enum_tours(dim: Int, path: Path) : List[Path] = {
-
- val allMovesFromCurrentPosition = legal_moves(dim, path, path.head);
-
- if (path.length == dim*dim) List(path) else {
-
- allMovesFromCurrentPosition.map( element => enum_tours(dim, element::path)).flatten ;
-
-
- }
- }
- println ( enum_tours(6, List((0,2))).size)
-}
-
-
-
-
-
-
-
-//(1b) Complete the function that calculates for a position
-// all legal onward moves that are not already in the path.
-// The moves should be ordered in a "clockwise" manner.
-
-//def legal_moves(dim: Int, path: Path, x: Pos) : List[Pos] = ...
-
-
-
-
-//some test cases
-//
-//assert(legal_moves(8, Nil, (2,2)) ==
-// List((3,4), (4,3), (4,1), (3,0), (1,0), (0,1), (0,3), (1,4)))
-//assert(legal_moves(8, Nil, (7,7)) == List((6,5), (5,6)))
-//assert(legal_moves(8, List((4,1), (1,0)), (2,2)) ==
-// List((3,4), (4,3), (3,0), (0,1), (0,3), (1,4)))
-//assert(legal_moves(8, List((6,6)), (7,7)) == List((6,5), (5,6)))
-
-
-//(1c) Complete the two recursive functions below.
-// They exhaustively search for knight's tours starting from the
-// given path. The first function counts all possible tours,
-// and the second collects all tours in a list of paths.
-
-//def count_tours(dim: Int, path: Path) : Int = ...
-
-
-//def enum_tours(dim: Int, path: Path) : List[Path] = ...