TweetFollow Us on Twitter

Apr 01 Challenge Volume Number: 17 (2001)
Issue Number: 4
Column Tag: Programmer's Challenge

Programmer's Challenge

By Bob Boonstra, Westford, MA

Crossword II

Several years ago we held a Programmers Challenge based on crossword puzzles. So when my son came home from school with an idea for a crossword Challenge, my first thought was that we had been there and done that. The old Challenge required readers to solve a crossword puzzle, fitting the available words into a predefined pattern, without the benefit of clues. My son's problem, to generate a crossword puzzle, is sufficiently different to make a potentially interesting Challenge.

The prototype for the code you should write is:

typedef struct Words {
   char *theWord;      /* null terminated string */
   short value;         /* points value for theWord */
} Words;

typedef struct WordPositions {
   short whichWord;            /* index in Words array of word being placed */
   short row;                     /* row in which the first letter of the word is placed */
   short col;                     /* col in which the first letter of the word is placed */
   short orientation;         /* 0==down, 1==across */
} WordPositions;

long /* numberOfWordPositions */ CrosswordII  (
   short puzzleSize,            /* puzzle has puzzleSize rows and columns */
   const Words words[],      /* words to be used to form the puzzle */
   short numWords,               /* number of words[] available */
   WordPositions positions[]      /* placement of words in puzzle */
);

The homework assignment that inspired this Challenge was from Chemistry class. Students were required to generate a 20x20 crossword puzzle using the names of the first 103 elements from the periodic table. Each word placed had a value equal to the atomic number for that element. So placing the word "lawrencium" earns you 103 points, "molybdenum" is worth only 42, but "lead" is worth 82. The assignment was to generate a crossword puzzle worth as many points as possible.

For the Challenge, we'll generalize the problem to work with an arbitrary list of words and arbitrarily assigned values. The puzzle dimension will be puzzleSize x puzzleSize instead of 20x20. You should decide which words to place where in the puzzle and return your word placements in the positions array, specifying in positions[].whichWord the index in words of the word being placed, the cell in which the first letter of the word is placed in positions[].row and positions[].col, and the direction the word is being placed in positions[].orientation. Your CrosswordII routine should return the number of words placed in the puzzle.

A few constraints: Each of the words will be at least 3 letters long and terminated with a zero byte. Every pair of adjacent letters in the puzzle you form must be part of some word. No word may occur more than once in the puzzle. Words may be placed horizontally or vertically, but not diagonally.

The winner will be the solution that earns the most points. Points will be based on the value of the words you place in your crossword puzzle, minus a penalty of 1% for each minute of execution time. The Challenge prize will be divided between the overall winner and the best scoring entry from a contestant that has not won the Challenge recently.

This will be a native PowerPC Challenge, using the CodeWarrior Pro 6 environment. Solutions may be coded in C, C++, or Pascal. You may provide a solution in Java instead, provided you also provide a test driver equivalent to the C code provided on the web for this problem.

Three Months Ago Winner

Congratulations to Willeke Rieken for winning the January Tetris Challenge. The Tetris Challenge required readers to provide a player for the classic Tetris game. Willeke actually won by default, as his was the only entry. As I've said before, you can't win if you don't play. With this win, Willeke vaults into second place in our Challenge points standings.

Willeke describes his solution as "low tech". The heavy lifting is done in his MovePiece routine, where he determines the position and orientation of the current piece that provides the best fit. His heuristic for best fit takes into consideration the number of unreachable empty spaces created by placing a piece, with special weighting against placements that create "deep pits". The solution does not take advantage of the opportunity to move a piece after it has been dropped, nor does it use the information provided about the next piece to be placed.

Top Contestants...

Listed here are the Top Contestants for the Programmer's Challenge, including everyone who has accumulated 20 or more points during the past two years. The numbers below include points awarded over the 24 most recent contests, including points earned by this month's entrants.

Rank Name Points
1. Munter, Ernst 281
2. Rieken, Willeke 85
3. Saxton, Tom 76
4. Maurer, Sebastian 68
5. Boring, Randy 52
6. Shearer, Rob 48
7. Taylor, Jonathan 36
8. Wihlborg, Charles 29

... and the Top Contestants Looking For a Recent Win

Starting this month, in order to give some recognition to other participants in the Challenge, we are also going to list the high scores for contestants who have accumulated points without taking first place in a Challenge. Listed here are all of those contestants who have accumulated 6 or more points during the past two years.

9. Downs, Andrew 12
10. Jones, Dennis 12
11. Day, Mark 10
12. Duga, Brady 10
13. Fazekas, Miklos 10
14. Flowers, Sue 10
15. Sadetsky, Gregory 10
16. Selengut, Jared 10
17. Strout, Joe 10
18. Hala, Ladislav 7
19. Miller, Mike 7
20. Nicolle, Ludovic 7
21. Schotsman, Jan 7
22. Widyyatama, Yudhi 7
23. Heithcock, JG 6

There are three ways to earn points: (1) scoring in the top 5 of any Challenge, (2) being the first person to find a bug in a published winning solution or, (3) being the first person to suggest a Challenge that I use. The points you can win are:

1st place 20 points
2nd place 10 points
3rd place 7 points
4th place 4 points
5th place 2 points
finding bug 2 points
suggesting Challenge 2 points

Here is Willeke's winning Tetris solution:

tetris.cp
Copyright © 2001
Willeke Rieken
/*
   a piece is dropped at each column and points are given for
   creating empty cells and adding height. points are subtracted
   for fitting in existing holes. the column with the lowest
   score wins. the moves to drop the piece in the winning
   column are placed in an array. in subsequent calls of Tetris
   the next move is returned.
   this is a low tech solution without using the next piece or
   the possibility to move a piece after it dropped. 
*/

#include <stdio.h>
#include <string.h>

#include "Tetris.h"

#define kPieceSize 7
#define kHalfPieceSize 3
#define kMaxBoardSizeSize 256
#define kMaxNrRotations 4

typedef struct PieceInfo {
   long pieceLeft, pieceRight, pieceTop, pieceBottom;
   long nrOfRorations;
} PieceInfo;

static const Piece *gGamePieces;
static MoveType gMovesToDo[(kMaxBoardSizeSize / 2) + 3];
   // (max board size/2) lefts or rights + 2 rotations + drop
static PieceInfo *gPieceInfo;
static long gNrMovesToDo, gMoveNr;
static long gLastPieceIndex, glastNextPieceIndex;
static long gNumRows, gNumCols;
static long gNumPieceTypes, gMaxPieceSize;

PieceFits

static short PieceFits(const Board gameBoard, long *theTopOfPieces,
                                    Piece theActivePiece,
                              long thePieceLeft, long thePieceRight,
                              long thePieceTop, long thePieceBottom,
                                    long theRow, long theCol,
                                    short theMustFitInBoard)
// check if the piece will fit on the board at
// position (theRow,theCol), if theMustFitInBoard then
// the total piece has to be on the board
{
   long   aRowOffset, aColOffset;
   long   aRow, aCol;

   aRowOffset = theRow - thePieceBottom - 1;
   aColOffset = theCol - kHalfPieceSize;
   for (aRow = thePieceTop; aRow <= thePieceBottom; aRow++)
      for (aCol = thePieceLeft; aCol <= thePieceRight; aCol++)
      {
         if (theActivePiece[aRow][aCol])
         {
            if (aRowOffset + aRow < 0)
               if (theMustFitInBoard)
                  return 0;
               else
                  break;
            if (theMustFitInBoard)
               if (aRowOffset + aRow >= 
                           theTopOfPieces[aColOffset + aCol])
                  return 0;
   if (gameBoard[aRowOffset + aRow][aColOffset + aCol] >= 0)
               return 0;
         }
      }
   return 1;
}

RotatePiece90

static void RotatePiece90(Piece theActivePiece,
                                       long *aPieceLeft, long *aPieceRight,
                                       long *aPieceTop, long *aPieceBottom)
// rotates the piece 90° clockwise
{
   Piece   aRotatedPiece;
   long   aRow, aCol;
   
   for (aRow = 0; aRow < kPieceSize; aRow++)
      for (aCol = 0; aCol < kPieceSize; aCol++)
         aRotatedPiece[aCol][kPieceSize - 1 - aRow] =
               theActivePiece[aRow][aCol];
   memcpy(theActivePiece, aRotatedPiece, sizeof(Piece));
         
   aRow = *aPieceLeft;
   *aPieceLeft = kPieceSize - 1 - *aPieceBottom;
   *aPieceBottom = *aPieceRight;
   *aPieceRight = kPieceSize - 1 - *aPieceTop;
   *aPieceTop = aRow;
}

RotatePiece180
static void RotatePiece180(Piece theActivePiece,
                                       long *aPieceLeft, long *aPieceRight,
                                       long *aPieceTop, long *aPieceBottom)
// rotates the piece 180°
{
   Piece   aRotatedPiece;
   long   aRow, aCol;
   
   for (aRow = 0; aRow < kPieceSize; aRow++)
      for (aCol = 0; aCol < kPieceSize; aCol++)
         aRotatedPiece[kPieceSize - 1 - aRow][kPieceSize - 1 - aCol] 
                  =   theActivePiece[aRow][aCol];
   memcpy(theActivePiece, aRotatedPiece, sizeof(Piece));
         
   aRow = *aPieceTop;
   *aPieceTop = kPieceSize - 1 - *aPieceBottom;
   *aPieceBottom = kPieceSize - 1 - aRow;
   aRow = *aPieceLeft;
   *aPieceLeft = kPieceSize - 1 - *aPieceRight;
   *aPieceRight = kPieceSize - 1 - aRow;
}

RotatePiece270
static void RotatePiece270(Piece theActivePiece,
                                       long *aPieceLeft, long *aPieceRight,
                                       long *aPieceTop, long *aPieceBottom)
// rotates the piece 90° counter clockwise
{
   Piece   aRotatedPiece;
   long   aRow, aCol;
   
   for (aRow = 0; aRow < kPieceSize; aRow++)
      for (aCol = 0; aCol < kPieceSize; aCol++)
         aRotatedPiece[kPieceSize - 1 - aCol][aRow] =
               theActivePiece[aRow][aCol];
   memcpy(theActivePiece, aRotatedPiece, sizeof(Piece));
         
   aRow = *aPieceTop;
   *aPieceTop = kPieceSize - 1 - *aPieceRight;
   *aPieceRight = *aPieceBottom;
   *aPieceBottom = kPieceSize - 1 - *aPieceLeft;
   *aPieceLeft = aRow;
}

FindCompletedLines
static void FindCompletedLines(const Board gameBoard,
                                             short theCompletedLines[kPieceSize],
                                             long *theNrCompletedLines,
                                             Piece theActivePiece,
                                             long thePieceLeft, long thePieceRight,
                                             long thePieceTop, long thePieceBottom,
                                             long theRow, long theCol)
// find the lines that are completed and will disappear after the piece dropped
{
   long   aRowOffset, aColOffset;
   long   aRow, aCol;

   aRowOffset = theRow - thePieceBottom - 1;
   aColOffset = theCol - kHalfPieceSize;

   for (aRow = 0; aRow < kPieceSize; aRow++)
      theCompletedLines[aRow] = 0;
   *theNrCompletedLines = 0;
      
   for (aRow = thePieceTop; aRow <= thePieceBottom; aRow++)
   {
      theCompletedLines[aRow] = 1;
      for (aCol = thePieceLeft; aCol <= thePieceRight; aCol++)
         if ((!theActivePiece[aRow][aCol]) &&
               (gameBoard[aRowOffset + aRow][aColOffset + aCol] == -1))
         {
            theCompletedLines[aRow] = 0;
            break;
         }
      if (theCompletedLines[aRow])
      {
         for (aCol = 0; aCol < aColOffset + thePieceLeft; aCol++)
            if (gameBoard[aRowOffset + aRow][aCol] == -1)
            {
               theCompletedLines[aRow] = 0;
               break;
            }
      }
      if (theCompletedLines[aRow])
      {
         for (aCol = aColOffset + thePieceRight + 1; 
                     aCol < gNumCols; aCol++)
            if (gameBoard[aRowOffset + aRow][aCol] == -1)
            {
               theCompletedLines[aRow] = 0;
               break;
            }
      }
      if (theCompletedLines[aRow])
         (*theNrCompletedLines)++;
   }
}

CountEmptySpaces
static long CountEmptySpaces(long *theTopOfPieces,
                                             short theCompletedLines[kPieceSize],
                                             Piece theActivePiece,
                                             long thePieceLeft, long thePieceRight,
                                             long thePieceTop, long thePieceBottom,
                                             long theRow, long theCol)
// count the empty cells as a result of the piece being dropped
// at theCol. don't include the empty cells that will be part
// of the big space at the top after de completed lines are removed
{
   long   aRowOffset, aColOffset;
   long   aRow, aCol, aNrOfEmptySpaces;

   aRowOffset = theRow - thePieceBottom - 1;
   aColOffset = theCol - kHalfPieceSize;
   aNrOfEmptySpaces = 0;
   for (aCol = thePieceLeft; aCol <= thePieceRight; aCol++)
   {
      short   aPieceInColumn = 0;
      
      for (aRow = thePieceTop; aRow <= thePieceBottom; aRow++)
         if (theActivePiece[aRow][aCol] && 
                     (!theCompletedLines[aRow]))
         {
            aPieceInColumn = 1;
            break;
         }
      if (aPieceInColumn)
      {
         aRow = thePieceTop;
         while ((!theActivePiece[aRow][aCol]) && 
                           (aRow <= thePieceBottom))
            aRow++;
         while ((aRow + aRowOffset < 
                           theTopOfPieces[aColOffset + aCol]) &&
                     (aRow <= thePieceBottom))
         {
            if (!theActivePiece[aRow][aCol])
               aNrOfEmptySpaces++;
            aRow++;
         }
         if (aRow + aRowOffset < theTopOfPieces[aColOffset + aCol])
            if ((theTopOfPieces[aColOffset + aCol] - aRow - aRowOffset) 
                              > gMaxPieceSize)
               aNrOfEmptySpaces += gMaxPieceSize;
            else
               aNrOfEmptySpaces += (theTopOfPieces[aColOffset + aCol] - 
                                                            aRow - aRowOffset);
      }
   }
   return aNrOfEmptySpaces;
}

CountTouches
static long CountTouches(const Board gameBoard,
                                    long *theTopOfPieces, Piece theActivePiece,
                                    long thePieceLeft, long thePieceRight,
                                    long thePieceTop, long thePieceBottom,
                                    long theRow, long theCol)
// count at how many cells the piece will touch the pieces on
// the board, subtract points for creating deep pits
{
   long   aRowOffset, aColOffset;
   long   aRow, aCol, aNrOfTouches;

   aRowOffset = theRow - thePieceBottom - 1;
   aColOffset = theCol - kHalfPieceSize;
   aNrOfTouches = 0;
   for (aRow = thePieceTop; aRow <= thePieceBottom; aRow++)
      for (aCol = thePieceLeft; aCol <= thePieceRight; aCol++)
         if (theActivePiece[aRow][aCol])
         {
            // touches on the left
            if (aColOffset + aCol == 0)
               aNrOfTouches++;
            else
               if (((aCol == thePieceLeft) ||
                        (!theActivePiece[aRow][aCol - 1])) &&
                     (gameBoard[aRowOffset + aRow][aColOffset + aCol - 1] 
                                                != -1))
                  aNrOfTouches++;
            // touches on the right
            if (aColOffset + aCol == gNumCols - 1)
               aNrOfTouches++;
            else
               if (((aCol == thePieceRight) ||
                        (!theActivePiece[aRow][aCol + 1])) &&
                     (gameBoard[aRowOffset + aRow][aColOffset + aCol + 1] 
                                                != -1))
                  aNrOfTouches++;
            // touches on the bottom
            if (aRowOffset + aRow == gNumRows - 1)
               aNrOfTouches++;
            else
               if (((aRow == thePieceBottom) ||
                        (!theActivePiece[aRow + 1][aCol])) &&
                     (gameBoard[aRowOffset + aRow + 1][aColOffset + aCol] 
                                                != -1))
                  aNrOfTouches++;
         }
   // check for deep pits
   if ((aColOffset + thePieceLeft > 0) &&
      (theTopOfPieces[aColOffset + thePieceLeft - 1] >
            aRowOffset + thePieceBottom + 1))
   {
      aNrOfTouches -= 
            ((theTopOfPieces[aColOffset + thePieceLeft - 1]) -
               (aRowOffset + thePieceTop + 1));
      aRow = thePieceTop;
      while (!theActivePiece[aRow][thePieceLeft])
      {
         aRow-;
         aNrOfTouches++;
      }
   }
   if ((aColOffset + thePieceRight < gNumCols - 1) &&
      (theTopOfPieces[aColOffset + thePieceRight + 1] >
            aRowOffset + thePieceBottom + 1))
   {
      aNrOfTouches -= ((theTopOfPieces[aColOffset + 
                                          thePieceRight + 1]) -
                                          (aRowOffset + thePieceTop + 1));
      aRow = thePieceTop;
      while (!theActivePiece[aRow][thePieceRight])
      {
         aRow-;
         aNrOfTouches++;
      }
   }
   return aNrOfTouches;
}

ValidMove
static short ValidMove(const Board gameBoard,
                                 short activePieceTypeIndex,
                                 long *theTopOfPieces, long theTopTopOfPieces,
                                 long theCol, long theRotation)
// check if the piece can reach its column without
// colliding with pieces on the board
{
   long   aCol, aRow, aNrMovesToDo;
   Piece   anActivePiece;
   long   aPieceLeft, aPieceRight, aPieceTop, aPieceBottom;

   memcpy(anActivePiece, gGamePieces[activePieceTypeIndex], 
                              sizeof(Piece));
   aPieceLeft = gPieceInfo[activePieceTypeIndex].pieceLeft;
   aPieceRight = gPieceInfo[activePieceTypeIndex].pieceRight;
   aPieceTop = gPieceInfo[activePieceTypeIndex].pieceTop;
   aPieceBottom = gPieceInfo[activePieceTypeIndex].pieceBottom;

   aRow = 1 - aPieceBottom;

   // count moves
   aNrMovesToDo = 0;
   switch (theRotation)
   {
      case 0:
         break;
      case 1:
         aNrMovesToDo++;
         break;
      case 2:
         aNrMovesToDo++;
         aNrMovesToDo++;
         break;
      case 3:
         aNrMovesToDo++;
         break;
   }
   if (theCol > gNumCols / 2)
      aNrMovesToDo += theCol - gNumCols / 2;
   else
      aNrMovesToDo += gNumCols / 2 - theCol;
      
   // check if the piece can move without hitting pieces on the board
   if (aNrMovesToDo >= theTopTopOfPieces)
   {
      switch (theRotation)
      {
         case 0:
            break;
         case 1:
            RotatePiece90(anActivePiece,
                                 &aPieceLeft, &aPieceRight,
                                 &aPieceTop, &aPieceBottom);
            aRow++;
            break;
         case 2:
            RotatePiece180(anActivePiece, &aPieceLeft,
                                 &aPieceRight, &aPieceTop,
                                 &aPieceBottom);
            aRow++;
            aRow++;
            break;
         case 3:
            RotatePiece270(anActivePiece,
                                 &aPieceLeft, &aPieceRight,
                                 &aPieceTop, &aPieceBottom);
            aRow++;
            break;
      }
      aRow += aPieceBottom;
      for (aCol = gNumCols / 2 + 1; aCol < theCol; aCol++)
         if (!PieceFits(gameBoard, theTopOfPieces, anActivePiece,
                              aPieceLeft, aPieceRight, aPieceTop, aPieceBottom,
                              aRow + (aCol - (gNumCols / 2 + 1)), aCol, 0))
            return 0;
      for (aCol = gNumCols / 2 - 1; aCol > theCol; aCol-)
         if (!PieceFits(gameBoard, theTopOfPieces, anActivePiece,
                              aPieceLeft, aPieceRight, aPieceTop, aPieceBottom,
                              aRow + ((gNumCols / 2 - 1) - aCol), aCol, 0))
            return 0;
   }
   return 1;
}

MovePiece
static void MovePiece(const Board gameBoard,
                                 short activePieceTypeIndex)
// determine the column for the piece and prepare the moves
{
   Piece   anActivePiece;
   long   aPieceLeft, aPieceRight, aPieceTop, aPieceBottom;
   long   aRow, aCol, aRotation;
   long   aTopOfPieces[kMaxBoardSizeSize];
   long   aBottomTopRow, aTopTopRow;
   long   aColScore[kMaxNrRotations][kMaxBoardSizeSize];
   long   aBestScore, aBestCol, aBestRotation;
   long   anExtraScore, aNrCompletedLines;
   short   aCompletedLines[kPieceSize];
   short   aValidMove;

   memcpy(anActivePiece, gGamePieces[activePieceTypeIndex],
             sizeof(Piece));
   
   aPieceLeft = gPieceInfo[activePieceTypeIndex].pieceLeft;
   aPieceRight = gPieceInfo[activePieceTypeIndex].pieceRight;
   aPieceTop = gPieceInfo[activePieceTypeIndex].pieceTop;
   aPieceBottom = gPieceInfo[activePieceTypeIndex].pieceBottom;

   // find top of pieces in board
   aBottomTopRow = 0;
   aTopTopRow = gNumCols;
   for (aCol = 0; aCol < gNumCols; aCol++)
   {
      aRow = 0;
      while ((aRow < gNumRows) &&
                  (gameBoard[aRow][aCol] == -1)) aRow++;
      aTopOfPieces[aCol] = aRow;
      if (aBottomTopRow < aRow)
         aBottomTopRow = aRow;
      if (aTopTopRow > aRow)
         aTopTopRow = aRow;
   }

   // find where the piece fits best
   for (aRotation = 0;
            aRotation < gPieceInfo[activePieceTypeIndex].nrOfRorations;
            aRotation++)
   {
      for (aCol = 0; aCol < gNumCols; aCol++)
      {
         aColScore[aRotation][aCol] = 1000000;
         if ((aCol >= kHalfPieceSize - aPieceLeft) &&
               (aCol < gNumCols - aPieceRight + kHalfPieceSize))
         {
            aRow = aTopOfPieces[aCol] + kPieceSize - 1;
            if (aRow > aBottomTopRow)
               aRow = aBottomTopRow;
      while ((!PieceFits(gameBoard, aTopOfPieces, anActivePiece,
                  aPieceLeft, aPieceRight, aPieceTop, aPieceBottom,
                              aRow, aCol, 1)) &&
                  (aRow >= 0))
               aRow-;
            if (aRow > (aPieceBottom - aPieceTop - 1))
            {
               aColScore[aRotation][aCol] =
                  ((aBottomTopRow - aRow) + 
                  (aPieceBottom - aPieceTop)) * 2;
               FindCompletedLines(gameBoard, aCompletedLines,
                        &aNrCompletedLines, anActivePiece,
                  aPieceLeft, aPieceRight, aPieceTop, aPieceBottom,
                        aRow, aCol);
               anExtraScore = CountEmptySpaces(aTopOfPieces,
                        aCompletedLines, anActivePiece,
                  aPieceLeft, aPieceRight, aPieceTop, aPieceBottom,
                        aRow, aCol);
               aColScore[aRotation][aCol] += anExtraScore * 5;
               anExtraScore = CountTouches(gameBoard,
                     aTopOfPieces, anActivePiece,
               aPieceLeft, aPieceRight, aPieceTop, aPieceBottom,
                        aRow, aCol);
               aColScore[aRotation][aCol] -= anExtraScore;
            }
         }
      }
      RotatePiece90(anActivePiece,
                  &aPieceLeft, &aPieceRight, &aPieceTop, &aPieceBottom);
   }
   aBestCol = 0;
   aBestRotation = 0;
   aValidMove = 0;
   while (!aValidMove)
   {
      aBestScore = 1000000;
      for (aRotation = 0;
            aRotation < gPieceInfo[activePieceTypeIndex].nrOfRorations;
            aRotation++)
         for (aCol = 0; aCol < gNumCols; aCol++)
            if (aColScore[aRotation][aCol] < aBestScore)
            {
               aBestScore = aColScore[aRotation][aCol];
               aBestCol = aCol;
               aBestRotation = aRotation;
            }
      if (aBestScore < 1000000)   // found valid move
      {
         if (ValidMove(gameBoard, activePieceTypeIndex,
                  aTopOfPieces, aTopTopRow, aBestCol, aBestRotation))
            aValidMove = 1;
         else
            aColScore[aBestRotation][aBestCol] = 1000000;
      }
      else
      {
         // no valid moves, give up
         aBestCol = gNumCols / 2;
         aBestRotation = 0;
         aValidMove = 1;
      }
   }
   
   // prepare moves
   gNrMovesToDo = 0;
   switch (aBestRotation)
   {
      case 1:
         gMovesToDo[gNrMovesToDo] = kRotateClockwise;
         gNrMovesToDo++;
         break;
      case 2:
         gMovesToDo[gNrMovesToDo] = kRotateClockwise;
         gNrMovesToDo++;
         gMovesToDo[gNrMovesToDo] = kRotateClockwise;
         gNrMovesToDo++;
         break;
      case 3:
         gMovesToDo[gNrMovesToDo] = kRotateCounterClockwise;
         gNrMovesToDo++;
         break;
   }
   if (aBestCol > gNumCols / 2)
      for (aCol = gNumCols / 2; aCol < aBestCol; aCol++)
      {
         gMovesToDo[gNrMovesToDo] = kMoveRight;
         gNrMovesToDo++;
      }
   else
      for (aCol = aBestCol; aCol < gNumCols / 2; aCol++)
      {
         gMovesToDo[gNrMovesToDo] = kMoveLeft;
         gNrMovesToDo++;
      }
   gMovesToDo[gNrMovesToDo] = kDrop;
   gNrMovesToDo++;
   gMovesToDo[gNrMovesToDo] = kNoMove;
   gNrMovesToDo++;
}

GetPieceInfo
static void GetPieceInfo()
// determine the bounds of the piece and if rotating
// the piece results in the same piece 
{
   long   i;

   for (i = 0; i < gNumPieceTypes; i++)
   {
      long   aPieceLeft = kPieceSize - 1, aPieceRight = 0;
      long   aPieceTop = kPieceSize - 1, aPieceBottom = 0;
      Piece   anActivePiece;
      long   aRow, aCol, aRowOffset, aColOffset;
      short   aPiecesMatch;

      memcpy(anActivePiece, gGamePieces[i], sizeof(Piece));
      for (aRow = 0; aRow < kPieceSize; aRow++)
         for (aCol = 0; aCol < kPieceSize; aCol++)
            if (anActivePiece[aRow][aCol])
            {
               if (aRow < aPieceTop)
                  aPieceTop = aRow;
               if (aRow > aPieceBottom)
                  aPieceBottom = aRow;
               if (aCol < aPieceLeft)
                  aPieceLeft = aCol;
               if (aCol > aPieceRight)
                  aPieceRight = aCol;
            }
      gPieceInfo[i].pieceLeft = aPieceLeft;
      gPieceInfo[i].pieceRight = aPieceRight;
      gPieceInfo[i].pieceTop = aPieceTop;
      gPieceInfo[i].pieceBottom = aPieceBottom;
      
      if (aPieceRight - aPieceLeft > gMaxPieceSize)
         gMaxPieceSize = aPieceRight - aPieceLeft;
      if (aPieceBottom - aPieceTop > gMaxPieceSize)
         gMaxPieceSize = aPieceBottom - aPieceTop;
      
      gPieceInfo[i].nrOfRorations = kMaxNrRotations;

      RotatePiece90(anActivePiece,
                  &aPieceLeft, &aPieceRight, &aPieceTop, &aPieceBottom);
      if ((aPieceRight - aPieceLeft) == (aPieceBottom - aPieceTop))
      {
         aPiecesMatch = 1;
         aRowOffset = gPieceInfo[i].pieceTop - aPieceTop;
         aColOffset = gPieceInfo[i].pieceLeft - aPieceLeft;
         for (aRow = aPieceTop; aRow <= aPieceBottom; aRow++)
            for (aCol = aPieceLeft; aCol <= aPieceRight; aCol++)
               if ((anActivePiece[aRow][aCol] &&
                        !gGamePieces[i][aRow + aRowOffset][aCol + 
                                    aColOffset]) ||
                     (!anActivePiece[aRow][aCol] &&
                        gGamePieces[i][aRow + 
                              aRowOffset][aCol + aColOffset]))
                  aPiecesMatch = 0;
         if (aPiecesMatch)
            gPieceInfo[i].nrOfRorations = 1;
      }
      if (gPieceInfo[i].nrOfRorations == kMaxNrRotations)
      {
         RotatePiece90(anActivePiece,
                  &aPieceLeft, &aPieceRight, &aPieceTop, &aPieceBottom);
         aPiecesMatch = 1;
         aRowOffset = gPieceInfo[i].pieceTop - aPieceTop;
         aColOffset = gPieceInfo[i].pieceLeft - aPieceLeft;
         for (aRow = aPieceTop; aRow <= aPieceBottom; aRow++)
            for (aCol = aPieceLeft; aCol <= aPieceRight; aCol++)
               if ((anActivePiece[aRow][aCol] &&
                        !gGamePieces[i][aRow + 
                                       aRowOffset][aCol + aColOffset]) ||
                     (!anActivePiece[aRow][aCol] &&
                        gGamePieces[i][aRow + 
                                       aRowOffset][aCol + aColOffset]))
                  aPiecesMatch = 0;
         if (aPiecesMatch)
            gPieceInfo[i].nrOfRorations = 2;
      }
   }
}

InitTetris
void InitTetris(
  short boardWidth,            /* width of board in cells */
  short boardHeight,         /* height of board in cells */
  short numPieceTypes,      /* number of types of pieces */
  const Piece gamePieces[],   /* pieces to play */
  long timeToPlay               /* game time, in milliseconds */
) {
   gNumRows = boardHeight;
   gNumCols = boardWidth;
   gNumPieceTypes = numPieceTypes;
   gGamePieces = gamePieces;
   gNrMovesToDo = 0;
   gMoveNr = 0;
   gLastPieceIndex = -1;
   glastNextPieceIndex = -1;
   gPieceInfo = new PieceInfo[gNumPieceTypes];
   gMaxPieceSize = 0;
   GetPieceInfo();
   gMaxPieceSize++;
}

Tetris
MoveType /* move active piece */ Tetris(
  const Board gameBoard,      
  /* current state of the game board,
     bottom row is [boardHeight-1], left column is [0] */
  short activePieceTypeIndex,   /* index into gamePieces of active piece */
  short nextPieceTypeIndex,      /* index into gamePieces of next piece */
  long pointsEarned,                     /* number of points earned thus far */
  long timeToGo                              /* time remaining, in milliseconds */
) {
   // try to detect a new piece,
   // will fail when a piece appears three times in a row
   if ((gLastPieceIndex != activePieceTypeIndex) ||
         (glastNextPieceIndex != nextPieceTypeIndex))
      gMoveNr = gNrMovesToDo;
   gLastPieceIndex = activePieceTypeIndex;
   glastNextPieceIndex = nextPieceTypeIndex;

   if (gMoveNr >= gNrMovesToDo)
   {
      // calculate the moves for a new piece
      MovePiece(gameBoard, activePieceTypeIndex);
      gMoveNr = 0;
   }
   // return next move
   return gMovesToDo[gMoveNr++];
}

TermTetris
void TermTetris(void) {
   delete[] gPieceInfo;
}
 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Microsoft Remote Desktop 8.0.16 - Connec...
With Microsoft Remote Desktop, you can connect to a remote PC and your work resources from almost anywhere. Experience the power of Windows with RemoteFX in a Remote Desktop client designed to help... Read more
Spotify 1.0.4.90. - Stream music, create...
Spotify is a streaming music service that gives you on-demand access to millions of songs. Whether you like driving rock, silky R&B, or grandiose classical music, Spotify's massive catalogue puts... Read more
djay Pro 1.1 - Transform your Mac into a...
djay Pro provides a complete toolkit for performing DJs. Its unique modern interface is built around a sophisticated integration with iTunes and Spotify, giving you instant access to millions of... Read more
Vivaldi 1.0.118.19 - Lightweight browser...
Vivaldi browser. In 1994, two programmers started working on a web browser. Our idea was to make a really fast browser, capable of running on limited hardware, keeping in mind that users are... Read more
Stacks 2.6.11 - New way to create pages...
Stacks is a new way to create pages in RapidWeaver. It's a plugin designed to combine drag-and-drop simplicity with the power of fluid layout. Features: Fluid Layout: Stacks lets you build pages... Read more
xScope 4.1.3 - Onscreen graphic measurem...
xScope is powerful set of tools that are ideal for measuring, inspecting, and testing on-screen graphics and layouts. Its tools float above your desktop windows and can be accessed via a toolbar,... Read more
Cyberduck 4.7 - FTP and SFTP browser. (F...
Cyberduck is a robust FTP/FTP-TLS/SFTP browser for the Mac whose lack of visual clutter and cleverly intuitive features make it easy to use. Support for external editors and system technologies such... Read more
Labels & Addresses 1.7 - Powerful la...
Labels & Addresses is a home and office tool for printing all sorts of labels, envelopes, inventory labels, and price tags. Merge-printing capability makes the program a great tool for holiday... Read more
teleport 1.2.1 - Use one mouse/keyboard...
teleport is a simple utility to let you use one single mouse and keyboard to control several of your Macs. Simply reach the edge of your screen, and your mouse teleports to your other Mac! The... Read more
Apple iMovie 10.0.8 - Edit personal vide...
With an all-new design, Apple iMovie lets you enjoy your videos like never before. Browse your clips more easily, instantly share your favorite moments, and create beautiful HD movies and Hollywood-... Read more

Use Batting Average and the Apple Watch...
Batting Average, by Pixolini, is designed to help you manage your statistics. Every time you go to bat, you can use your Apple Watch to track  your swings, strikes, and hits. [Read more] | Read more »
Celebrate Studio Pango's 3rd Annive...
It is time to party, Pangoland pals! Studio Pango is celebrating their 3rd birthday and their gift to you is a new update to Pangoland. [Read more] | Read more »
Become the World's Most Important D...
Must Deliver, by cherrypick games, is a top-down endless-runner witha healthy dose of the living dead. [Read more] | Read more »
SoundHound + LiveLyrics is Making its De...
SoundHound Inc. has announced that SoundHound + LiveLyrics, will be one of the first third-party apps to hit the Apple Watch. With  SoundHound you'll be able to tap on your watch and have the app recognize the music you are listening to, then have... | Read more »
Adobe Joins the Apple Watch Lineup With...
A whole tidal wave of apps are headed for the Apple Watch, and Adobe has joined in with 3 new ways to enhance your creativity and collaborate with others. The watch apps pair with iPad/iPhone apps to give you total control over your Adobe projects... | Read more »
Z Steel Soldiers, Sequel to Kavcom'...
Kavcom has released Z Steel Soldiers, which continues the story of the comedic RTS originally created by the Bitmap Brothers. [Read more] | Read more »
Seene Lets You Create 3D Images With You...
Seene, by Obvious Engineering, is a 3D capture app that's meant to allow you to create visually stunning 3D images with a tap of your finger, and then share them as a 3D photo, video or gif. [Read more] | Read more »
Lost Within - Tips, Tricks, and Strategi...
Have you just downloaded Lost Within and are you in need of a guiding hand? While it’s not the toughest of games out there you might still want some helpful tips to get you started. [Read more] | Read more »
Entertain Your Pet With Your Watch With...
The Petcube Camera is a device that lets you use live video to check in on your pet, talk to them, and play with them using a laser pointer - all while you're away. And the Petcube app is coming to the Apple Watch, so you'll be able to hang out with... | Read more »
Now You Can Manage Your Line2 Calls With...
You'll be able to get your Line2 cloud phone service on the Apple Watch very soon. The watch app can send and receive messages using hands-free voice dictation, or by selecting from a list of provided responses. [Read more] | Read more »

Price Scanner via MacPrices.net

Intel Compute Stick: A New Mini-Computing For...
The Intel Compute Stick, a new pocket-sized computer based on a quad-core Intel Atom processor running Windows 8.1 with Bing, is available now through Intel Authorized Dealers across much of the... Read more
Heal to Launch First One-Touch House Call Doc...
Santa Monica, California based Heal, a pioneer in on-demand personal health care services — will offer the first one-touch, on-demand house call doctor app for the Apple Watch. Heal’s Watch app,... Read more
Mac Notebooks: Avoiding MagSafe Power Adapter...
Apple Support says proper usage, care, and maintenance of Your Mac notebook’s MagSafe power adapter can substantially increase the the adapter’s service life. Of course, MagSafe itself is an Apple... Read more
12″ Retina MacBook In Shootout With Air And P...
BareFeats’ rob-ART morgan has posted another comparison of the 12″ MacBook with other Mac laptops, noting that the general goodness of all Mac laptops can make which one to purchase a tough decision... Read more
FileMaker Go for iPad and iPhone: Over 1.5 Mi...
FileMaker has announced that its FileMaker Go for iPad and iPhone app has surpassed 1.5 million downloads from the iTunes App Store. The milestone confirms the continued popularity of the FileMaker... Read more
Sale! 13-inch 2.7GHz Retina MacBook Pro for $...
 Best Buy has the new 2015 13″ 2.7GHz/128GB Retina MacBook Pro on sale for $1099 – $200 off MSRP. Choose free shipping or free local store pickup (if available). Price for online orders only, in-... Read more
Minimalist MacBook Confirms Death of Steve Jo...
ReadWrite’s Adriana Lee has posted a eulogy for the “Digital Hub” concept Steve Jobs first proposed back in 2001, declaring the new 12-inch MacBook with its single, over-subscribed USB-C port to be... Read more
13-inch 2.7GHz Retina MacBook Pro for $1234 w...
Adorama has the 13″ 2.7GHz/128GB Retina MacBook Pro in stock for $1234.99 ($65 off MSRP) including free shipping plus a free LG external DVD/CD optical drive. Adorama charges sales tax in NY & NJ... Read more
13-inch 2.5GHz MacBook Pro available for $999...
 Adorama has the 13-inch 2.5GHz MacBook Pro on sale for $999 including free shipping plus NY & NJ sales tax only. Their price is $100 off MSRP. Read more
Save up to $600 with Apple refurbished Mac Pr...
The Apple Store is offering Apple Certified Refurbished Mac Pros for up to $600 off the cost of new models. An Apple one-year warranty is included with each Mac Pro, and shipping is free. The... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Support Technician IV - Jack Henry a...
Job Description Jack Henry & Associates is seeking an Apple Support Technician. This position while acting independently, ensures the proper day-to-day control of Read more
*Apple* Client Systems Solution Specialist -...
…drive revenue and profit in assigned sales segment and/or region specific to the Apple brand and product sets. This person will work directly with CDW Account Managers Read more
*Apple* Software Support - Casper (Can work...
…experience . Full knowledge of Mac OS X and prior . Mac OSX / Server . Apple Remote Desktop . Process Documentation . Ability to prioritize multiple tasks in a fast pace Read more
*Apple* Software Support - Xerox Corporation...
…Imaging experience Full knowledge of Mac OS X and prior Mac OSX / Server Apple Remote Desktop Process Documentation Ability to prioritize multiple tasks in a fast pace Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.