Merge pull request #476 from jcoehoorn/patch-3

Create program.vb

02_Amazing/vbnet/program.vb

@@ -0,0 +1,295 @@
+Imports System
+
+Module Program
+
+    Enum Directions
+        SolveAndReset = 0
+        Left = 1
+        Up = 2
+        Right = 3
+        Down = 4
+    End Enum
+
+    'Program State
+    Dim Width As Integer = 0, Height As Integer = 0, Q As Integer = 0, CellsVisited As Integer = 2, curCol As Integer, curRow As Integer = 1
+    Dim SolutionCompleted As Boolean = False
+    Dim CellVisitHistory(,) As Integer
+    Dim CellState(,) As Integer
+
+    Dim rnd As New Random()
+
+    Public ReadOnly Property BlockedLeft As Boolean
+        Get
+            Return curCol - 1 = 0 OrElse CellVisitHistory(curCol - 1, curRow) <> 0
+        End Get
+    End Property
+    Public ReadOnly Property BlockedAbove As Boolean
+        Get
+            Return curRow - 1 = 0 OrElse CellVisitHistory(curCol, curRow - 1) <> 0
+        End Get
+    End Property
+    Public ReadOnly Property BlockedRight As Boolean
+        Get
+            Return curCol = Width OrElse CellVisitHistory(curCol + 1, curRow) <> 0
+        End Get
+    End Property
+    'Note: "BlockedBelow" does NOT include checking if we have a solution!
+    Public ReadOnly Property BlockedBelow As Boolean
+        Get
+            Return curRow = Height OrElse CellVisitHistory(curCol, curRow + 1) <> 0
+        End Get
+    End Property
+    Public ReadOnly Property OnBottomRow As Boolean
+        Get
+            Return curRow.Equals(Height)
+        End Get
+    End Property
+
+    Sub Main(args As String())
+        Const header As String =
+"             AMAZING PROGRAM
+ CREATIVE COMPUTING  MORRISTOWN, NEW JERSEY
+
+
+
+"
+        Console.WriteLine(header)
+
+        While Width <= 1 OrElse Height <= 1
+            Console.Write("WHAT ARE YOUR WIDTH AND LENGTH? ")
+
+            'We no longer have the old convenient INPUT command, so need to parse out the inputs
+            Dim parts = Console.ReadLine().Split(","c).Select(Function(s) Convert.ToInt32(s.Trim())).ToList()
+            Width = parts(0)
+            Height = parts(1)
+
+            If Width <= 1 OrElse Height <= 1 Then Console.WriteLine($"MEANINGLESS DIMENSIONS.  TRY AGAIN.{vbCrLf}")
+        End While
+
+        ReDim CellVisitHistory(Width, Height), CellState(Width, Height)
+
+        Console.WriteLine("
+
+")
+
+        curCol = rnd.Next(1, Width + 1) 'Starting X position
+        CellVisitHistory(curCol, 1) = 1
+        Dim startXPos As Integer = curCol 'we need to know this at the end to print opening line
+
+        Dim keepGoing As Boolean = True
+        While keepGoing
+            If BlockedLeft Then
+                keepGoing = ChoosePath_BlockedToTheLeft()
+            ElseIf BlockedAbove Then
+                keepGoing = ChoosePath_BlockedAbove()
+            ElseIf BlockedRight Then
+                keepGoing = ChoosePath_BlockedToTheRight()
+            Else
+                keepGoing = SelectRandomDirection(Directions.Left, Directions.Up, Directions.Right) 'Go anywhere but down
+            End If
+        End While
+
+        PrintFinalResults(startXPos)
+    End Sub
+
+    Public Sub ResetCurrentPosition()
+        Do
+            If curCol <> Width Then 'not at the right edge
+                curCol += 1
+            ElseIf curRow <> Height Then 'not at the bottom
+                curCol = 1
+                curRow += 1
+            Else
+                curCol = 1
+                curRow = 1
+            End If
+        Loop While CellVisitHistory(curCol, curRow) = 0
+    End Sub
+
+    Dim methods() As Func(Of Boolean) = {AddressOf MarkSolvedAndResetPosition, AddressOf GoLeft, AddressOf GoUp, AddressOf GoRight, AddressOf GoDown}
+    Public Function SelectRandomDirection(ParamArray possibles() As Directions) As Boolean
+        Dim x As Integer = rnd.Next(0, possibles.Length)
+        Return methods(possibles(x))()
+    End Function
+
+    Public Function ChoosePath_BlockedToTheLeft() As Boolean
+        If BlockedAbove Then
+            If BlockedRight Then
+                If curRow <> Height Then
+                    If CellVisitHistory(curCol, curRow + 1) <> 0 Then ' Can't go down, but not at the edge...blocked. Reset and try again
+                        ResetCurrentPosition()
+                        Return True
+                    Else
+                        Return GoDown()
+                    End If
+                ElseIf SolutionCompleted Then 'Can't go Down (there's already another solution)
+                    ResetCurrentPosition()
+                    Return True
+                Else 'Can't go LEFT, UP, RIGHT, or DOWN, but we're on the bottom and there's no solution yet
+                    Return MarkSolvedAndResetPosition()
+                End If
+            ElseIf BlockedBelow Then
+                Return GoRight()
+            ElseIf Not OnBottomRow Then
+                Return SelectRandomDirection(Directions.Right, Directions.Down)
+            ElseIf SolutionCompleted Then 'Can only go right, and we're at the bottom
+                Return GoRight()
+            Else 'Can only go right, we're at the bottom, and there's not a solution yet
+                Return SelectRandomDirection(Directions.Right, Directions.SolveAndReset)
+            End If
+            '== Definitely can go Up ==
+        ElseIf BlockedRight Then
+            If BlockedBelow Then
+                Return GoUp()
+            ElseIf Not OnBottomRow Then
+                Return SelectRandomDirection(Directions.Up, Directions.Down)
+            ElseIf SolutionCompleted Then 'We're on the bottom row, can only go up
+                Return GoUp()
+            Else 'We're on the bottom row, can only go up, but there's no solution 
+                Return SelectRandomDirection(Directions.Up, Directions.SolveAndReset)
+            End If
+            '== Definitely can go Up and Right ==
+        ElseIf BlockedBelow Then
+            Return SelectRandomDirection(Directions.Up, Directions.Right)
+        ElseIf Not OnBottomRow Then
+            Return SelectRandomDirection(Directions.Up, Directions.Right, Directions.Down)
+        ElseIf SolutionCompleted Then 'at the bottom, but already have a solution
+            Return SelectRandomDirection(Directions.Up, Directions.Right)
+        Else
+            Return SelectRandomDirection(Directions.Up, Directions.Right, Directions.SolveAndReset)
+        End If
+    End Function
+
+    Public Function ChoosePath_BlockedAbove() As Boolean
+        'No need to check the left side, only called from the "keepGoing" loop where LEFT is already cleared
+        If BlockedRight Then
+            If BlockedBelow Then
+                Return GoLeft()
+            ElseIf Not OnBottomRow Then
+                Return SelectRandomDirection(Directions.Left, Directions.Down)
+            ElseIf SolutionCompleted Then 'Can't go down because there's already a solution
+                Return GoLeft()
+            Else 'At the bottom, no solution yet...
+                Return SelectRandomDirection(Directions.Left, Directions.SolveAndReset)
+            End If
+        ElseIf BlockedBelow Then
+            Return SelectRandomDirection(Directions.Left, Directions.Right)
+        ElseIf Not OnBottomRow Then
+            Return SelectRandomDirection(Directions.Left, Directions.Right, Directions.Down)
+        ElseIf SolutionCompleted Then
+            Return SelectRandomDirection(Directions.Left, Directions.Right)
+        Else
+            Return SelectRandomDirection(Directions.Left, Directions.Right, Directions.SolveAndReset)
+        End If
+    End Function
+
+    Public Function ChoosePath_BlockedToTheRight() As Boolean
+        'No need to check Left or Up, only called from the "keepGoing" loop where LEFT and UP are already cleared
+        If BlockedRight Then 'Can't go Right -- why? we knew this when calling the function
+            If BlockedBelow Then
+                Return SelectRandomDirection(Directions.Left, Directions.Up)
+            ElseIf Not OnBottomRow Then
+                Return SelectRandomDirection(Directions.Left, Directions.Up, Directions.Down)
+            ElseIf SolutionCompleted Then
+                Return SelectRandomDirection(Directions.Left, Directions.Up)
+            Else
+                Return SelectRandomDirection(Directions.Left, Directions.Up, Directions.SolveAndReset)
+            End If
+        Else 'Should never get here
+            Return SelectRandomDirection(Directions.Left, Directions.Up, Directions.Right) 'Go Left, Up, or Right (but path is blocked?)
+        End If
+    End Function
+
+    Public Sub PrintFinalResults(startPos As Integer)
+        For i As Integer = 0 To Width - 1
+            If i = startPos Then Console.Write(".  ") Else Console.Write(".--")
+        Next
+        Console.WriteLine(".")
+
+        If Not SolutionCompleted Then 'Pick a random exit
+            Dim X As Integer = rnd.Next(1, Width + 1)
+            If CellState(X, Height) = 0 Then
+                CellState(X, Height) = 1
+            Else
+                CellState(X, Height) = 3
+            End If
+        End If
+
+        For j As Integer = 1 To Height
+            Console.Write("I")
+            For i As Integer = 1 To Width
+                If CellState(i, j) < 2 Then
+                    Console.Write("  I")
+                Else
+                    Console.Write("   ")
+                End If
+            Next
+            Console.WriteLine()
+
+            For i As Integer = 1 To Width
+                If CellState(i, j) = 0 OrElse CellState(i, j) = 2 Then
+                    Console.Write(":--")
+                Else
+                    Console.Write(":  ")
+                End If
+            Next
+            Console.WriteLine(".")
+        Next
+    End Sub
+
+    Public Function GoLeft() As Boolean
+        curCol -= 1
+        CellVisitHistory(curCol, curRow) = CellsVisited
+        CellsVisited += 1
+        CellState(curCol, curRow) = 2
+        If CellsVisited > Width * Height Then Return False
+        Q = 0
+        Return True
+    End Function
+
+    Public Function GoUp() As Boolean
+        curRow -= 1
+        CellVisitHistory(curCol, curRow) = CellsVisited
+        CellsVisited += 1
+        CellState(curCol, curRow) = 1
+        If CellsVisited > Width * Height Then Return False
+        Q = 0
+        Return True
+    End Function
+
+    Public Function GoRight() As Boolean
+        CellVisitHistory(curCol + 1, curRow) = CellsVisited
+        CellsVisited += 1
+        If CellState(curCol, curRow) = 0 Then CellState(curCol, curRow) = 2 Else CellState(curCol, curRow) = 3
+        curCol += 1
+        If CellsVisited > Width * Height Then Return False
+        Return ChoosePath_BlockedToTheLeft()
+    End Function
+
+    Public Function GoDown() As Boolean
+        If Q = 1 Then Return MarkSolvedAndResetPosition()
+
+        CellVisitHistory(curCol, curRow + 1) = CellsVisited
+        CellsVisited += 1
+        If CellState(curCol, curRow) = 0 Then CellState(curCol, curRow) = 1 Else CellState(curCol, curRow) = 3
+        curRow += 1
+        If CellsVisited > Width * Height Then Return False
+        Return True
+    End Function
+
+    Public Function MarkSolvedAndResetPosition() As Boolean
+        ' AlWAYS returns true
+        SolutionCompleted = True
+        Q = 1
+        If CellState(curCol, curRow) = 0 Then
+            CellState(curCol, curRow) = 1
+            curCol = 1
+            curRow = 1
+            If CellVisitHistory(curCol, curRow) = 0 Then ResetCurrentPosition()
+        Else
+            CellState(curCol, curRow) = 3
+            ResetCurrentPosition()
+        End If
+        Return True
+    End Function
+End Module