Microsoft Small Basic

Program Listing:

' 8-Queens 0.2
' Copyright (c) 2012 Nonki Takahashi
'
' History :
' 0.2 2013/01/03 Rewrote for 8-Queens probrem. ()
' 0.1 2012/08/04 Code for chessmen written in hexadecimal.
' 0.0 2012/08/04 25-line version created. (CLP327)
'
GraphicsWindow.Title = "8-Queens 0.2"
GraphicsWindow.BackgroundColor = "#004C00"
GraphicsWindow.BrushColor = "Black"
oNum = Controls.AddTextBox(440, 30)
num = 12345678
Controls.SetTextBoxText(oNum, num)
InitBoard()
CheckValid()
DrawBoard()
Controls.TextTyped = OnTextTyped

Sub OnTextTyped
  num = Controls.GetTextBoxText(oNum)
  len = Text.GetLength(num)
  correct = "False"
  If len = 8 Then
    correct = "True"
    For i = 1 To 8
      If Text.IsSubText(num, Text.GetSubText("12345678", i, 1)) = "False" Then
        correct = "False"
      EndIf
    EndFor
  EndIf
  If correct Then
    board = ""
    For c = 1 To 8
      board[Text.GetSubText(num, c, 1)][Text.GetSubText("abcdefgh", c, 1)] = "BQ"
    EndFor
    CheckValid()
    DrawBoard()
  EndIf
EndSub

Sub CheckValid
  valid = "True"
  For c1 = 1 To 8
    For c2 = c1 + 1 To 8
      r1 = Text.GetSubText(num, c1, 1)
      r2 = Text.GetSubText(num, c2, 1)
      dc = Math.Abs(c2 - c1)
      dr = Math.Abs(r2 - r1)
      If dc = dr Then
        valid = "False"
        board[r1][Text.GetSubText("abcdefgh", c1, 1)] = "RQ"
        board[r2][Text.GetSubText("abcdefgh", c2, 1)] = "RQ"
      EndIf
    EndFor
  EndFor
EndSub

Sub DrawBoard
  For r = 8 To 1 Step - 1
    y = pos["y0"] + (8 - r) * size
    For c = 1 To 8
      x = pos["x0"] + (c - 1) * size
      GraphicsWindow.BrushColor = color[Math.Remainder((c + r), 2)]
      GraphicsWindow.FillRectangle(x, y, size, size)
      p = board[r][Text.GetSubText("abcdefgh", c, 1)]
      If p <> "" Then
        GraphicsWindow.BrushColor = color[Text.GetSubText(p, 1, 1)]
        sHex = pieces[Text.GetSubText(p, 2, 1)]
        Math_Hex2Dec()
        GraphicsWindow.DrawText(x, y - size * 0.12, Text.GetCharacter(iDec))
      EndIF
    EndFor
  EndFor
EndSub

Sub InitChessmen
  size = 48   ' font height and square size
  GraphicsWindow.FontSize = size
  pieces = "P=265F;N=265E;B=265D;R=265C;Q=265B;K=265A;"
EndSub

Sub InitBoard
  pos = "x0=30;y0=30;" ' left, top
  For c = 1 To 8
    board[c][Text.GetSubText("abcdefgh", c, 1)] = "BQ"
  EndFor
  color = "W=White;B=Black;R=Red;0=SaddleBrown;1=BurlyWood;"
  InitChessmen()
EndSub

Sub Math_Hex2Dec
  ' Math | Convert sHex to iDec
  iDec = 0
  iLen = Text.GetLength(sHex)
  For iPtr = 1 To iLen
    iDec = iDec * 16 + Text.GetIndexOf("0123456789ABCDEF", Text.GetSubText(sHex, iPtr, 1)) - 1
  EndFor
EndSub

Sub DumpBoard
  For r = 8 To 1 Step -1
    For c = 1 To 8
      If board[r][Text.GetSubText("abcdefgh", c, 1)] <> "" Then
        TextWindow.Write(board[r][Text.GetSubText("abcdefgh", c, 1)] + " ")
      Else
        TextWindow.Write(" ")
      EndIf
    EndFor
    TextWindow.WriteLine("")
  EndFor
EndSub