Data commit

Task/Maze-solving/PureBasic/maze-solving.basic

@@ -0,0 +1,110 @@
+;code from the maze generation task is place here in its entirety before the rest of the code
+
+Procedure displayMazePath(Array maze(2), List Path.POINT())
+  Protected x, y, vWall.s, hWall.s
+  Protected mazeWidth = ArraySize(maze(), 1), mazeHeight = ArraySize(maze(), 2)
+  Protected Dim mazeOutput.mazeOutput(mazeHeight)
+  Protected Dim mazeRow.mazeOutput(0)
+  Static pathChars.s = "@^>v<"
+
+  For y = 0 To mazeHeight
+    makeDisplayMazeRow(mazeRow(), maze(), y): mazeOutput(y) = mazeRow(0)
+  Next
+
+  If ListSize(path())
+    FirstElement(path())
+    Protected prevPath.POINT = path()
+
+    While NextElement(path())
+      x = path()\x - prevPath\x
+      y = path()\y - prevPath\y
+      Select x
+        Case -1: dirTaken = #dir_W
+        Case 1: dirTaken = #dir_E
+        Default
+          If y < 0
+            dirTaken = #dir_N
+          Else
+            dirTaken = #dir_S
+          EndIf
+      EndSelect
+      hWall = mazeOutput(prevPath\y)\hWall
+      mazeOutput(prevPath\y)\hWall = Left(hWall, prevPath\x * #cellDWidth + 2) + Mid(pathChars, dirTaken + 1, 1) + Right(hWall, Len(hWall) - (prevPath\x * #cellDWidth + 3))
+      prevPath = path()
+    Wend
+    hWall = mazeOutput(prevPath\y)\hWall
+    mazeOutput(prevPath\y)\hWall = Left(hWall, prevPath\x * #cellDWidth + 2) + Mid(pathChars, #dir_ID + 1, 1) + Right(hWall, Len(hWall) - (prevPath\x * #cellDWidth + 3))
+
+    For y = 0 To mazeHeight
+      PrintN(mazeOutput(y)\vWall): PrintN(mazeOutput(y)\hWall)
+    Next
+  EndIf
+EndProcedure
+
+Procedure solveMaze(Array maze(2), *start.POINT, *finish.POINT, List Path.POINT())
+  Protected mazeWidth = ArraySize(maze(), 1), mazeHeight = ArraySize(maze(), 2)
+  Dim visited(mazeWidth + 1, mazeHeight + 1) ;includes padding for easy border detection
+
+  Protected i
+  ;mark outside border as already visited (off limits)
+  For i = 1 To mazeWidth
+    visited(i, 0) = #True: visited(i, mazeHeight + 1) = #True
+  Next
+  For i = 1 To mazeHeight
+    visited(0, i) = #True: visited(mazeWidth + 1, i) = #True
+  Next
+
+  Protected x = *start\x, y = *start\y, nextCellDir
+  visited(x + offset(#visited, #dir_ID)\x, y + offset(#visited, #dir_ID)\y) = #True
+
+  ClearList(path())
+  Repeat
+    If x = *finish\x And y = *finish\y
+      AddElement(path())
+      path()\x = x: path()\y = y
+      Break ;success
+    EndIf
+
+    nextCellDir = #firstDir - 1
+    For i = #firstDir To #numDirs
+      If Not visited(x + offset(#visited, i)\x, y + offset(#visited, i)\y)
+        If maze(x + offset(#wall, i)\x, y + offset(#wall, i)\y) & wallvalue(i) <> #Null
+          nextCellDir = i: Break ;exit for/next search
+        EndIf
+      EndIf
+    Next
+
+    If nextCellDir >= #firstDir
+      visited(x + offset(#visited, nextCellDir)\x, y + offset(#visited, nextCellDir)\y) = #True
+
+      AddElement(path())
+      path()\x = x: path()\y = y
+
+      x + offset(#maze, nextCellDir)\x: y + offset(#maze, nextCellDir)\y
+    ElseIf ListSize(path()) > 0
+      x = path()\x: y = path()\y
+      DeleteElement(path())
+    Else
+      Break
+    EndIf
+  ForEver
+
+EndProcedure
+
+;demonstration
+If OpenConsole()
+  Define.POINT start, finish
+  start\x = Random(mazeWidth - 1): start\y = Random(mazeHeight - 1)
+  finish\x = Random(mazeWidth - 1): finish\y = Random(mazeHeight - 1)
+  NewList Path.POINT()
+  solveMaze(maze(), start, finish, path())
+  If ListSize(path()) > 0
+    PrintN("Solution found for path between (" + Str(start\x) + ", " + Str(start\y) + ") and (" + Str(finish\x) + ", " + Str(finish\y) + ")")
+    displayMazePath(maze(), path())
+  Else
+    PrintN("No solution found for path between (" + Str(start\x) + ", " + Str(start\y) + ") and (" + Str(finish\x) + ", " + Str(finish\y) + ")")
+  EndIf
+
+  Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input()
+  CloseConsole()
+EndIf