//===========================================================================
//                                                                     SUDOKU
//                                                                24 May 2006
//===========================================================================
// Place a StringGrid component on the Form (5th icon under Additional tab)
// Look in "Help" under "TStringGrid"
// Property changes:
// Align = alCustom
// FixedCols = 0, FixedRows = 0
// DefaultColWidth = 30, DefaultRowHeight = 30
// ColCount = 9, RowCount = 9
// ScrollBars = ssNone
// Height = 282, Width = 282
// Font->Size = 18
// Options: goEditing = true
//
// You need to paste in an OpenDialog component (Dialogs tab)
// You need to paste in a SaveDialog component (Dialogs tab)
//===========================================================================

//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop
#include "Unit1.h"
#include <fstream.h>                   // for streaming file handling
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
   : TForm(Owner)
{
   DoubleBuffered = true;             // eliminates flicker
}
//---------------------------------------------------------------------------

//===========================================================================
//                                                                  VARIABLES
//===========================================================================

bool cellSelected = true;
int numSelected;
int col, row;
int enteredCol, enteredRow;
int tally[10] = {0};                  // tally for duplicate digits

//===========================================================================
//                                                                  FUNCTIONS
//===========================================================================

//--------------------------------------------------------------------- CLEAR
void clear (void) {
   for (int i = 0; i < 10; i++) {
      for (int j = 0; j < 10; j++) {
         Form1->StringGrid1->Cells[i][j] = "";
      }
   }
}

//---------------------------------------------------------------- DRAW LINES
void drawLines (void) {
   Form1->StringGrid1->Canvas->Pen->Color = clBlack;
   Form1->StringGrid1->Canvas->Pen->Width = 3;
   Form1->StringGrid1->Canvas->MoveTo(0, 92);
   Form1->StringGrid1->Canvas->LineTo(282, 92);
   Form1->StringGrid1->Canvas->MoveTo(0, 184);
   Form1->StringGrid1->Canvas->LineTo(282, 184);
   Form1->StringGrid1->Canvas->MoveTo(92, 0);
   Form1->StringGrid1->Canvas->LineTo(92, 282);
   Form1->StringGrid1->Canvas->MoveTo(184, 0);
   Form1->StringGrid1->Canvas->LineTo(184, 282);
   Application->ProcessMessages();
}

//--------------------------------------------------------------- ERROR FOUND
void errorFound (void) {
   Form1->Color = clRed;
   Application->ProcessMessages();
   Sleep(200);
   Application->ProcessMessages();
   Form1->Color = clBtnFace;
   Form1->StringGrid1->Cells[enteredCol][enteredRow] = "";
   drawLines();
   Application->ProcessMessages();
}

//-------------------------------------------------------------- TALLY DIGITS
void clearTally (void) {
   for (int i = 0; i < 10; i++) tally[i] = 0;
}

//---------------------------------------------------------- CHECK FOR ERRORS
void checkForErrors (void) {

   // check columns
   for (int col = 0; col < 9; col++) {
      clearTally();
      for (int row = 0; row < 9; row++) {
         if (Form1->StringGrid1->Cells[col][row] != "") {
            int num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            tally[num]++;
            if (tally[num] > 1) errorFound();
         }
      }
   }

   // check rows
   for (int row = 0; row < 9; row++) {
      clearTally();
      for (int col = 0; col < 9; col++) {
         if (Form1->StringGrid1->Cells[col][row] != "") {
            int num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            tally[num]++;
            if (tally[num] > 1) errorFound();
         }
      }
   }

   // check block 1:
   clearTally();
   for (int col = 0; col < 3; col++) {
      for (int row = 0; row < 3; row++) {
         if (Form1->StringGrid1->Cells[col][row] != "") {
            int num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            tally[num]++;
            if (tally[num] > 1) errorFound();
         }
      }
   }

   // check block 2:
   clearTally();
   for (int col = 3; col < 6; col++) {
      for (int row = 0; row < 3; row++) {
         if (Form1->StringGrid1->Cells[col][row] != "") {
            int num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            tally[num]++;
            if (tally[num] > 1) errorFound();
         }
      }
   }

   // check block 3:
   clearTally();
   for (int col = 6; col < 9; col++) {
      for (int row = 0; row < 3; row++) {
         if (Form1->StringGrid1->Cells[col][row] != "") {
            int num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            tally[num]++;
            if (tally[num] > 1) errorFound();
         }
      }
   }

   // check block 4:
   clearTally();
   for (int col = 0; col < 3; col++) {
      for (int row = 3; row < 6; row++) {
         if (Form1->StringGrid1->Cells[col][row] != "") {
            int num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            tally[num]++;
            if (tally[num] > 1) errorFound();
         }
      }
   }

   // check block 5:
   clearTally();
   for (int col = 3; col < 6; col++) {
      for (int row = 3; row < 6; row++) {
         if (Form1->StringGrid1->Cells[col][row] != "") {
            int num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            tally[num]++;
            if (tally[num] > 1) errorFound();
         }
      }
   }

   // check block 6:
   clearTally();
   for (int col = 6; col < 9; col++) {
      for (int row = 3; row < 6; row++) {
         if (Form1->StringGrid1->Cells[col][row] != "") {
            int num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            tally[num]++;
            if (tally[num] > 1) errorFound();
         }
      }
   }

   // check block 7:
   clearTally();
   for (int col = 0; col < 3; col++) {
      for (int row = 6; row < 9; row++) {
         if (Form1->StringGrid1->Cells[col][row] != "") {
            int num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            tally[num]++;
            if (tally[num] > 1) errorFound();
         }
      }
   }

   // check block 8:
   clearTally();
   for (int col = 3; col < 6; col++) {
      for (int row = 6; row < 9; row++) {
         if (Form1->StringGrid1->Cells[col][row] != "") {
            int num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            tally[num]++;
            if (tally[num] > 1) errorFound();
         }
      }
   }

   // check block 9:
   clearTally();
   for (int col = 6; col < 9; col++) {
      for (int row = 6; row < 9; row++) {
         if (Form1->StringGrid1->Cells[col][row] != "") {
            int num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            tally[num]++;
            if (tally[num] > 1) errorFound();
         }
      }
   }
   drawLines();
}

//--------------------------------- SAVE THE STUFF THAT WE COMPUTED FUNCTION
void saveStuff (void) {
   if (Form1->SaveDialog1->Execute()) {
      ofstream outfile(Form1->SaveDialog1->FileName.c_str());
      int num;
      for (int row = 0; row < 9; row++) {
         for (int col = 0; col < 9; col++) {
            if (Form1->StringGrid1->Cells[col][row] == "") num = 0;
            else num = StrToInt(Form1->StringGrid1->Cells[col][row]);
            outfile << num << " ";
         }
         outfile << endl;
      }
      outfile.close();
   }
}

//--------------------------------------- OPEN THE STUFF THAT WE SAVED BUTTON
void openStuff (void) {
   if (Form1->OpenDialog1->Execute()) {
   ifstream infile(Form1->OpenDialog1->FileName.c_str());
   int num;
   for (int row = 0; row < 9; row++) {
      for (int col = 0; col < 9; col++) {
         infile >> num;
         if (num == 0) Form1->StringGrid1->Cells[col][row] = "";
         else Form1->StringGrid1->Cells[col][row] = num;
      }
   }
   infile.close();
   }
}

//===========================================================================
//                                                             EVENT HANDLERS
//===========================================================================

//-------------------------------------------------------- STRING GRID KEY UP
void __fastcall TForm1::StringGrid1KeyUp(TObject *Sender, WORD &Key,
      TShiftState Shift)
{
   drawLines();
}

//----------------------------------------------------- STRING GRID DRAW CELL
void __fastcall TForm1::StringGrid1DrawCell(TObject *Sender, int ACol,
      int ARow, TRect &Rect, TGridDrawState State)
{
   drawLines();
}

//------------------------------------------------- STRING GRID SET EDIT TEXT
void __fastcall TForm1::StringGrid1SetEditText(TObject *Sender, int ACol,
      int ARow, const AnsiString Value)
{
   if (Value == "1" || Value == "2" || Value == "3" ||
       Value == "4" || Value == "5" || Value == "6" ||
       Value == "7" || Value == "8" || Value == "9") {
       enteredCol = ACol;
       enteredRow = ARow;
       checkForErrors();
   }
   else {
      StringGrid1->Cells[ACol][ARow] = "";
   }
}

//--------------------------------------------------------------- SAVE BUTTON
void __fastcall TForm1::ButtonSaveClick(TObject *Sender)
{
   saveStuff();
}

//--------------------------------------------------------------- OPEN BUTTON
void __fastcall TForm1::ButtonOpenClick(TObject *Sender)
{
   openStuff();
}

//-------------------------------------------------------------- CLEAR BUTTON
void __fastcall TForm1::ButtonClearClick(TObject *Sender)
{
   clear();
}

//---------------------------------------------------------------------------