diff -r 126d0e47ac85 -r 274c865b3878 main_solution4/knight4.scala
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main_solution4/knight4.scala	Wed Nov 02 21:49:42 2022 +0000
@@ -0,0 +1,33 @@
+// Part 4 about finding a single tour on "mutilated" chessboards
+//==============================================================
+
+object M4d { 
+
+// !!! Copy any function you need from file knight1.scala !!!
+// !!! or knight2.scala or knight3.scala                  !!! 
+//
+// If you need any auxiliary function, feel free to 
+// implement it, but do not make any changes to the
+// templates below.
+
+type Pos = (Int, Int)
+type Path = List[Pos]
+
+def print_board(dim: Int, path: Path): Unit = {
+  println()
+  for (i <- 0 until dim) {
+    for (j <- 0 until dim) {
+      print(f"${path.reverse.indexOf((i, j))}%4.0f ")
+    }
+    println()
+  } 
+}
+
+// ADD YOUR CODE BELOW
+//======================
+
+// (10)
+def one_tour_pred(dim: Int, path: Path, n: Int, pred: Pos => Boolean): Option[Path] = ???
+
+
+}