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Feb 98 Challenge

Volume Number: 14 (1998)
Issue Number: 2
Column Tag: Programmer's Challenge

Programmer's Challenge

by Bob Boonstra, Westford, MA

Image Decoder

This month's Challenge is much easier to state than it will be to implement. Your task this month is to write a decoder for Graphics Interchange Format images. GIF is a data stream-oriented file format used to define the transmission protocol of LZW-encoded bitmap data. Your code will read a file containing a GIF and draw the image in an offscreen graphics world. There are two versions of the GIF specification; this Challenge includes only the earlier and more common GIF87a format, not the GIF89a format. The format description is too long to include here, but you can find the GIF87a specification at: ftp://ftp.ncsa.uiuc.edu/misc/file.formats/graphics.formats/gif87a.doc

Other useful information on graphics formats in general is available at: http://www.cis.ohio-state.edu/hypertext/faq/usenet/graphics/fileformats-faq/top.html

The prototype for the code you should write is:

#include <QDOffscreen.h>
#include <stdio.h>
GWorldPtr ReadImage(FILE *inputFile);

The inputFile will have been opened for you in binary mode by the calling routine. ReadImage should read and parse the image, create a GWorld with the appropriate color table, draw the image in the GWorld, and return a GWorld pointer to the calling routine. The solution that correctly decodes a variety of images in the least amount of execution time will be the winner.

I thought for some time about the Compuserve / Unisys / LZW patent controverty before selecting this topic for the Challenge. The LZW algorithm used in GIF compression is patented by Unisys, and Unisys requires that any commercial software product that uses this algorithm, including software that reads GIF images, requires a license from Unisys. Freely distributed software does not require a license. Since the Challenge doesn't result in a software product, much less a commercial product, I decided to go ahead with this exploration of decoding efficiency.

This will be a native PowerPC Challenge, using the latest CodeWarrior environment. Solutions must be coded in C, C++, or Pascal. This Challenge was suggested by Peter Lewis, who earns 2 Challenge points for the suggestion.

Three Months Ago Winner

Congratulations to Jeff Mallett (Boulder Creek, CA) for submitting the winning entry to the Pente(tm) Challenge. The objective was to accumulate, in minimum execution time, the most points in a round-robin tournament of the board game Pente(tm). With only three entries, the tournament required only six games for each player to compete against each other player twice, once playing first and once playing second. Both the winning entry and the third-place entry by Randy Boring employed an alpha-beta search technique to find the best move, and both entries were successful in winning most of their games. Jeff's entry, however, was more efficient about pruning the search tree and therefore required significantly less execution time than Randy's entry. Since a point was deducted for each second of execution time, the winning entry lost significantly fewer points for inefficiency. In addition, the scoring algorithm in Jeff's AddStone routine takes advantage of all three methods of scoring points: captures, winning by placing 5 stones in a row, and leaving sequences of 4-in-a-row on the board at the conclusion of a game. His solution earned more points as a result, even though it won the same number of games as Randy's.

The table below lists the number of tournament wins, points earned, cumulative score, code size, data size, and programming language for each entry. The number in parentheses after the entrant's name is the total number of Challenge points earned in all Challenges to date prior to this one.

Name               Wins   Points   Score  Code  Data  Language
Jeff Mallett (74)    3      33     32.03  4872  7923    C
Sebastian Maurer     0      10      9.97  4860  208     C++
Randy Boring (66)    3      23   -374.90  7672  2649    C

Top 20 Contestants

Here are the Top Contestants for the Programmer's Challenge. The numbers below include points awarded over the 24 most recent contests, including points earned by this month's entrants. The scores have been adjusted to correct an error made in assigning points for the Stratego Challenge printed in the November issue.

Rank Name               Points
 1.  Munter, Ernst        200  
 2.  Boring, Randy         73
 3.  Cooper, Greg          61
 4.  Lewis, Peter          59
 5.  Mallett, Jeff         50
 6.  Nicolle, Ludovic      48
 7.  Murphy, ACC           34
 8.  Gregg, Xan            33
 9.  Antoniewicz, Andy     24
10.  Day, Mark             20
11.  Higgins, Charles      20
12.  Larsson, Gustav       20
13.  Studer, Thomas        20
14.  Gundrum, Eric         15
15.  Hart, Alan            14
16.  O'Connor, Turlough    14
17.  Picao, Miguel Cruz    14
18.  Saxton, Tom           12
19.  Cutts, Kevin          11
20.  8-way tie             10

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 Jeff's winning solution:

MyPente.c
Copyright © 1997 Jeff Mallett
//
// Do a depth=1 search to sort moves. Then do a higher
// depth alpha-beta search to select the best move.
//
// Plays for score rather than to win. For example,
// doesn't try to win by getting 5 captures since
// there is no score incentive for this. It could be
// retuned to play for a win instead.

#include "Pente.h"

#define SEARCH_DEPTH 4
enum {
 _FRIEND = 0x0001,
 _ENEMY = 0x0002,
 _EMPTY = 0x0004,
 _WALL  = 0x0008
};

#define BORDER    1
#define BORDERS    2
#define INFINITY   32600
#define NA      0
#define MAX_CELLS   (31 + BORDERS) * (31 + BORDERS)

#define ESTIMATE_PLUS 1
#define WIN      2000
#define CAPTURE_SCORE 240
#define VULNERABLE   150

static short CHAIN_SCORE2[3][3] = {  //[color][open]
 { NA, NA, NA },
 { -1, -9, -2 },      // FRIEND
 { 1, 9, 2 }      // ENEMY
};
static short CHAIN_SCORE3[3][3] = {  //[color][open]
 { NA, NA, NA },
 { 3, 16, 40 },      // FRIEND
 { -2,-10,-30 }      // ENEMY
};
static short CHAIN_SCORE4[3][3] = {  //[color][open]
 {  NA, NA, NA },
 { 230, 240, 250 },  // FRIEND
 { -150,-155,-160 }  // ENEMY
};
static short CHAIN_SCORE5[3] = {    //[color]
 NA, WIN, -WIN
};
//                 1  2  3  4
static short BLOCK_SCORE[5] = { NA, 0, 14, 14, 22};
static short THREATS[] = {
 NA, NA,
 25, // 2: tria
 30, // 3: half-open four
 350, // 4: double trias
 370, // 5: tria + half-open four
 450, // 6: tessera or 2 half-open fours
 500, 500, 500, 500, 500, 500, 500, 500, 500, 500
};

static short gPreScore[MAX_CELLS], gEstimates[MAX_CELLS];
static short *gEstimatesStart, *gEstimatesEnd;
static short gBoard[MAX_CELLS], *gBoardStart, *gBoardEnd;
static short *gFirstStone, *gLastStone;
static short *gKillers[SEARCH_DEPTH], gPreviousThreats;
static short gDirections[8], *gDirectionsEnd;
static short gMoveNum, gScore, gStartDepth;
static short gBoardHalfSize, gSideLength, gBoardMax;
static short gCumCapturesFriend, gCumCapturesEnemy;
static short gAdjustment, gSE;

#define ADJUST(a)    ( (a) + gAdjustment )
#define TRANSLATE(x, y) \
 (gSideLength * ADJUST(y) + ADJUST(x))
#define GET_INDEX(p) ((p) - gBoard)
#define GET_X(i)   ( ((i) % gSideLength) - gAdjustment )
#define GET_Y(i)   ( ((i) / gSideLength) - gAdjustment )
#define UPDATE_ENDPOINTS(pSq, a, b) \
 if (pSq < a) a = pSq; \
 if (pSq > b) b = pSq

#define OPPONENT(side) (3 - (side))
#define OCCUPIED(x)   ((x) & (_FRIEND | _ENEMY))
#define EMPTY(x)    ((x) == _EMPTY)

// gChanges -- Array of unsigned longs containing data to
// undo moves
//   list of:
//     <pointer to position> <old position value>
//   terminated by a OL
static unsigned long gChanges[256], *gChangesEnd;
#define PUSH(x)    *(gChangesEnd++) = (x)
#define START_SAVE  PUSH(0L)
#define PUSH_SQ(pSq) \
  { PUSH((long)*(pSq)); PUSH((unsigned long)(pSq)); }
#define POP      *(--gChangesEnd)
#define TOP      *gChangesEnd

static short * ChooseNextMove();
static short AddStone(short alpha, short beta, short *pSq,
        short color, short depth,
        short capturesFriend, short capturesEnemy,
        short *firstStone, short *lastStone);
static long MyFindCaptures(Capture capture[], short *pSq,
        short us, short them);
static Boolean MyFindFive(short *pSq, short color);

InitPente
void InitPente(
 long boardHalfSize  /* e.g., 9 for a 19x19 board */
       /* all coordinates between -boardHalfSize
        and +boardHalfSize */
) {
 short i, j, *pSq;
 
 gBoardHalfSize = boardHalfSize;
 gSideLength = boardHalfSize * 2 + 1 + BORDERS;
 gSE = gSideLength + 1;
 gDirections[0] = -gSE;                // NW
 gDirections[1] = -gSideLength;        // N
 gDirections[2] = -gSideLength + 1;     // NE
 gDirections[3] = -1;                // W
 gDirections[4] = gSE;                // SE
 gDirections[5] = gSideLength;        // S
 gDirections[6] = gSideLength - 1;      // SW
 gDirections[7] = 1;                  // E
 gDirectionsEnd = &gDirections[8];
 
 gBoardMax = gSideLength * gSideLength;
 i = (gSideLength + 1) * BORDER;
 gBoardStart = &gBoard[i];
 gBoardEnd = &gBoard[gBoardMax - i];
 gEstimatesStart = &gEstimates[i];
 gEstimatesEnd = &gEstimates[gBoardMax - i];
 gFirstStone = gBoardEnd;
 gLastStone = gBoardStart;
 
 pSq = gBoard;
 do {
  *pSq = _WALL;
 } while (++pSq != gBoardStart);
 do {
  *pSq = _EMPTY;
 } while (++pSq != gBoardEnd);
 do {
  *pSq = _WALL;
 } while (++pSq < &gBoard[gBoardMax]);
 for (i = BORDER + boardHalfSize * 2 + 1;
    i<gBoardMax-gSideLength; i += gSideLength)
  for (j=0; j<BORDERS; ++j)
   gBoard[i+j] = _WALL;
 gCumCapturesFriend = gCumCapturesEnemy = gMoveNum = 0;
 gAdjustment = gBoardHalfSize + BORDER;
 gStartDepth = SEARCH_DEPTH - 1;
}

Pente
void Pente(
 Point opponentsMove,      /* your opponent moved here */
 Boolean playingFirst,      /* ignore opponentMove */
 Point *yourMove,          /* return your move here */
 Capture claimCaptures[],    /* return captured pairs here */
 long *numCaptures,       /* return # of claimCaptures */
 Boolean *claimVictory     /* return true if you claim
               victory with this move */
) {
 Point move;
 Capture opponentCaptures[8];
 
 short *pSq, *pNewSq, *d;
 short score, bestScore, i;
 short *pBestMove;
 
 *numCaptures = 0;
 *claimVictory = false;
 if (playingFirst) { // *** MOVE 1
  move.h = move.v = 0;
  pSq = &gBoard[TRANSLATE(0, 0)];
  *pSq = _FRIEND;
  UPDATE_ENDPOINTS(pSq, gFirstStone, gLastStone);
  *yourMove = move;
  gMoveNum = 1;
  return;
 }
 
 i = TRANSLATE(opponentsMove.h, opponentsMove.v);
 pSq = &gBoard[i];
 *pSq = _ENEMY;
 UPDATE_ENDPOINTS(pSq, gFirstStone, gLastStone);
 ++gMoveNum;

 if (gMoveNum == 1) { // *** MOVE 2
  move.h = move.v = -2;
  pSq = &gBoard[TRANSLATE(-2, -2)];
  *pSq = _FRIEND;
  UPDATE_ENDPOINTS(pSq, gFirstStone, gLastStone);
  *yourMove = move;
  gMoveNum = 2;
  return;
 }
 
 if (gMoveNum == 2) { // *** MOVE 3
  if (opponentsMove.v < opponentsMove.h) {
   if (opponentsMove.v < -opponentsMove.h) {
    // top triangle
    move.h = 0;
    move.v = 4;
   } else {
    // right triangle
    move.h = -4;
    move.v = 0;
   }
  } else {
   if (opponentsMove.v >= -opponentsMove.h) {
    // bottom triangle
    move.h = 0;
    move.v = -4;
   } else {
    // left triangle
    move.h = 4;
    move.v = 0;
   }
  }
  pSq = &gBoard[TRANSLATE(move.h, move.v)];
  *pSq = _FRIEND;
  UPDATE_ENDPOINTS(pSq, gFirstStone, gLastStone);
  *yourMove = move;
  gMoveNum = 3;
  return;
 }

 gChangesEnd = gChanges;
 gCumCapturesEnemy +=
   MyFindCaptures(opponentCaptures, &gBoard[i],
           _ENEMY, _FRIEND);
 for (pSq = gEstimatesStart; pSq != gEstimatesEnd; ++pSq)
  *pSq = 0;
 for (pSq = gFirstStone; pSq <= gLastStone; ++pSq)
  if (OCCUPIED(*pSq)) {
   d = gDirections;
   do {
    pNewSq = pSq + *d;
    if (EMPTY(*pNewSq)) {
     gEstimates[GET_INDEX(pNewSq)] += ESTIMATE_PLUS;
     pNewSq += *d;
     if (EMPTY(*pNewSq)) {
      gEstimates[GET_INDEX(pNewSq)] += ESTIMATE_PLUS;
     }
    }
   } while (++d != gDirectionsEnd);
  }

 for (pSq = gBoardStart; pSq != gBoardEnd; ++pSq)
  if (gEstimates[GET_INDEX(pSq)]) {
   i = GET_INDEX(pSq);
   gScore = gEstimates[i];
   gPreScore[i] = AddStone(-INFINITY, INFINITY, pSq,
            _FRIEND, 0, gCumCapturesFriend,
            gCumCapturesEnemy, gFirstStone,
            gLastStone);
  }

 for (i=0; i<SEARCH_DEPTH; ++i)
  gKillers[i] = NULL;
 bestScore = -INFINITY;
 pBestMove = NULL;
 pSq = ChooseNextMove();
 while (pSq) {
  i = GET_INDEX(pSq);
  gScore = gEstimates[i];
  score = AddStone(-INFINITY, -bestScore, pSq, _FRIEND,
       gStartDepth, gCumCapturesFriend,
       gCumCapturesEnemy, gFirstStone, gLastStone);
  gEstimates[i] = -1; // searched
  if (score > bestScore) {
   bestScore = score;
   pBestMove = pSq;
  }
  pSq = ChooseNextMove();
 }
  
 if (bestScore == -INFINITY) {
  for (pSq = gBoardStart; pSq != gBoardEnd; ++pSq)
   if (EMPTY(*pSq) && !gEstimates[GET_INDEX(pSq)]) {
    gScore = 0;
    score = AddStone(-INFINITY, -bestScore, pSq, _FRIEND,
                  gStartDepth, gCumCapturesFriend,
                  gCumCapturesEnemy, gFirstStone, gLastStone);
    if (score > bestScore) {
     bestScore = score;
     pBestMove = pSq;
    }
   }
  if (bestScore == -INFINITY) {
   DebugStr("\p no move found - Pente");
   return; //no move
  }
 }
 
 *pBestMove = _FRIEND;
 UPDATE_ENDPOINTS(pBestMove, gFirstStone, gLastStone);
 i = GET_INDEX(pBestMove);
 move.h = GET_X(i);
 move.v = GET_Y(i);
 *yourMove = move;
 ++gMoveNum;
 // find captures
 *numCaptures = MyFindCaptures(claimCaptures, pBestMove,
          _FRIEND, _ENEMY);
 gCumCapturesFriend += *numCaptures;
 if (gCumCapturesFriend >= 5) {
  *claimVictory = true;
 } else {
  *claimVictory = MyFindFive(pBestMove, _FRIEND);
 }
}

TermPente
void TermPente(void) { }

ChooseNextMove
short * ChooseNextMove()
{
 short i, *pSq;
 short *found = NULL;
 short high = -INFINITY;
 for (pSq = gBoardStart; pSq != gBoardEnd; ++pSq) {
  i = GET_INDEX(pSq);
  if (gEstimates[i] > 0 && gPreScore[i] > high) {
   found = pSq;
   high = gPreScore[i];
  }
 }
 return found;
}

AddStone
// Alpha-beta search routine
// returns score of how good it is for color
// alpha and beta apply for the opponent after the move
// is made
// gScore is absolute: + for _FRIEND
short AddStone(short alpha, short beta, short *pSq,
    short color, short depth, short capturesFriend,
    short capturesEnemy, short *firstStone,
    short *lastStone)
{
 register short *pNewSq, *d;
 short x, bestScore, t, *pEnd;
 short open, *killer;
 short threats, blocks, vulnerable;
 short opponent = OPPONENT(color);
 short saveScore = gScore;
  
 START_SAVE;
 threats = blocks = vulnerable = 0;
 d = gDirections;
 do {
  pNewSq = pSq + *d;
  
  if (*pNewSq == color) { // Next to friend
   if (d <= &gDirections[3]) {
    x = 1;
    open = 0;
    for (pNewSq += *d; *pNewSq == color; pNewSq += *d)
     ++x;
    if (EMPTY(*pNewSq))
     open = 1;
    for (pNewSq = pSq + *(d+4); *pNewSq == color;
       pNewSq += *(d+4))
     ++x;
    if (EMPTY(*pNewSq))
     ++open;
   } else {
    t = *(pSq + *(d-4));
    if (t == color)
     continue;
    x = 1;
    open = 0;
    if (EMPTY(t))
     open = 1;
    for (pNewSq += *d; *pNewSq == color; pNewSq += *d)
     ++x;
    if (EMPTY(*pNewSq))
     ++open;
   }
   
   switch (x) {
    case 1:  // 2-in-a-row
     gScore += CHAIN_SCORE2[color][open];
     if (open == 1)
      ++vulnerable;
     break;
    case 2:  // 3-in-a-row
     gScore += CHAIN_SCORE3[color][open];
     if (open == 2)
      threats += 2;        // tria = 2
     break;
    case 3:  // 4-in-a-row
     gScore += CHAIN_SCORE4[color][open];
     threats += open * 3;  // tessera = 6, half-open = 3
     break;
    default:  // 5-in-a-row (or more)
     gScore += CHAIN_SCORE5[color];
     threats = -99;        // game over
     break;
   }
   
  } else if (*pNewSq == opponent) {  // Next to enemy
   x = 1;
   for (pNewSq += *d; *pNewSq == opponent; pNewSq += *d)
    ++x;
    
   if (EMPTY(*pNewSq)) {
    blocks += BLOCK_SCORE[x];
   } else if (x == 2 && *pNewSq == color) {
    t = CAPTURE_SCORE;
    if (color != _FRIEND)
     t = -t;
    gScore += t;
    if (color == _FRIEND) {
     if (++capturesFriend >= 5) {
      threats = -99;  // game over
     }
    } else {  // color == _ENEMY
     if (++capturesEnemy >= 5) {
      threats = -99;  // game over
     }
    }
    if (depth) {
     pNewSq = pSq + *d;
     PUSH_SQ(pNewSq);
     *pNewSq = _EMPTY;
     pNewSq += *d;
     PUSH_SQ(pNewSq);
     *pNewSq = _EMPTY;
    }
   }
  }
 } while (++d != gDirectionsEnd);
  
 if (threats < 0) {
  // Game over
  bestScore = gScore;
  if (color != _FRIEND)
   bestScore = -bestScore;
  goto RESTORE;
 }
   
  // Not forced to make a bad move
 if (color == _FRIEND) {
  if (gScore < saveScore)
   gScore = saveScore;
 } else if (gScore > saveScore)
  gScore = saveScore;
 if (depth) {
  // Add stone
  PUSH_SQ(pSq);
  *pSq = color;
  UPDATE_ENDPOINTS(pSq, firstStone, lastStone);
  --depth; 
  gPreviousThreats = threats;
  bestScore = -INFINITY;
  // Killer move?
  killer = gKillers[depth];
  if (killer && EMPTY(*killer)) {
   saveScore = gScore;
    bestScore = AddStone(-beta, -alpha, killer,
           opponent, depth, capturesFriend,
           capturesEnemy, firstStone, lastStone);
   gScore = saveScore;
   if (bestScore > alpha) {
    if (bestScore >= beta) {
     bestScore = -bestScore;
     goto RESTORE;
    }
    alpha = bestScore;
   }
  }
  
  pEnd = lastStone + gSE;
  if (pEnd >= gBoardEnd)
   pEnd = gBoardEnd - 1;
  pSq = firstStone - gSE;
  if (pSq < gBoardStart)
   pSq = gBoardStart;
  do {
   if (EMPTY(*pSq) && pSq != killer) {
    d = gDirections;
    do {
     pNewSq = pSq + *d;
     if (OCCUPIED(*pNewSq) &&
        (*(pNewSq + *d) == *pNewSq ||
         *(pSq  - *d) == *pNewSq))
      break;
    } while (++d != gDirectionsEnd);
    if (d != gDirectionsEnd) {
     saveScore = gScore;
      t = AddStone(-beta, -alpha, pSq, opponent,
         depth, capturesFriend, capturesEnemy,
         firstStone, lastStone);
     gScore = saveScore;
     if (t > bestScore) {
      bestScore = t;
      if (t > alpha) {
       if (t >= beta) {
        gKillers[depth] = pSq;
        break;
       }
       if (depth >= gStartDepth-1)
        gKillers[depth] = pSq;
       alpha = t;
      }
     }
    }
   }
  } while (++pSq <= pEnd);
  if (bestScore == -INFINITY) {
   ++depth;
   goto TERMINAL;
  }
  bestScore = -bestScore;
  
 } else { // !depth
TERMINAL:
  bestScore = gScore;
  if (color != _FRIEND)
   bestScore = -bestScore;

  // Winning threats
  if (gPreviousThreats >= 5) {
   bestScore -= THREATS[gPreviousThreats];
  } else if (threats >= 5) {
   bestScore += THREATS[threats];
  } else if (gPreviousThreats == 4) {
   bestScore -= THREATS[gPreviousThreats];
  } else if (threats == 4) {
   bestScore += THREATS[threats];
  } else if (gPreviousThreats) {
   bestScore -= THREATS[gPreviousThreats];
  } else if (threats) {
   bestScore += THREATS[threats];
  }
  bestScore += blocks - vulnerable * VULNERABLE;
 }
 
RESTORE: 
 while (POP) {
  pSq = (short *)TOP;
  *pSq = POP;
 }
  
 return bestScore;
}

MyFindCaptures
long MyFindCaptures(Capture capture[], short *pSq,
          short us, short them)
{
 short i, *p1, *p2;
 short myCaptures = 0;
 short *d = gDirections;
 
 do {
  p1 = pSq + *d;
  if (*p1 == them) {
   p2 = p1 + *d;
   if (*p2 == them && *(p2 + *d) == us) {
    *p1 = *p2 = _EMPTY;
    i = GET_INDEX(p1);
    capture[myCaptures].stone1.h = GET_X(i);
    capture[myCaptures].stone1.v = GET_Y(i);
    i = GET_INDEX(p2);
    capture[myCaptures].stone2.h = GET_X(i);
    capture[myCaptures].stone2.v = GET_Y(i);
    ++myCaptures;
   }
  }
 } while (++d != gDirectionsEnd);
 return myCaptures;
}

MyFindFive
Boolean MyFindFive(short *pSq, short color)
{
 short x, *d, *pNewSq, i;
 
 d = gDirections;
 i = 0;
 do {
  x = 1;
  for (pNewSq = pSq + *d; *pNewSq == color; pNewSq += *d)
   ++x;
  for (pNewSq = pSq + *(d+4); *pNewSq == color;
     pNewSq += *(d+4))
   ++x;
  if (x >= 5)
   return true;
  ++d;
 } while (++i < 4);
 return false;
}
 

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Pinegrow Web Designer is desktop app that lets you mockup and design webpages faster with multi-page editing, CSS and LESS styling, and smart components for Bootstrap, Foundation, Angular JS, and... Read more
ExpanDrive 5.4.1 - Access cloud storage...
ExpanDrive builds cloud storage in every application, acts just like a USB drive plugged into your Mac. With ExpanDrive, you can securely access any remote file server directly from the Finder or... Read more
MacUpdate Desktop 6.1.3 - Search and ins...
MacUpdate Desktop 6 brings seamless 1-click app installs and version updates to your Mac. With a free MacUpdate account and MacUpdate Desktop 6, Mac users can now install almost any Mac app on... Read more
VOX 2.8.6 - Music player that supports m...
VOX just sounds better! The beauty is in its simplicity, yet behind the minimal exterior lies a powerful music player with a ton of features and support for all audio formats you should ever need.... Read more
Espionage 3.6.6 - Simple, state-of-the-a...
Espionage offers state-of-the-art encryption and plausible deniability for your confidential data. Sometimes, encrypting your data isn't enough to protect it. That's why Espionage 3 goes beyond data... Read more
VOX 2.8.6 - Music player that supports m...
VOX just sounds better! The beauty is in its simplicity, yet behind the minimal exterior lies a powerful music player with a ton of features and support for all audio formats you should ever need.... Read more
MacUpdate Desktop 6.1.3 - Search and ins...
MacUpdate Desktop 6 brings seamless 1-click app installs and version updates to your Mac. With a free MacUpdate account and MacUpdate Desktop 6, Mac users can now install almost any Mac app on... Read more

3 tips for catching the gnarliest waves...
Like a wave breaking on the shore, Tidal Rider swept its way onto the App Store charts this week settling firmly in the top 10. It’s a one-touch high score-chaser in which you pull surfing stunts while dodging seagulls and collecting coins. The... | Read more »
The beginner's guide to destroying...
Age of Heroes: Conquest is 5th Planet Games’ all new turn-based multiplayer RPG, full of fantasy exploration, guild building, and treasure hunting. It’s pretty user-friendly as far as these games go, but when you really get down to it, you’ll find... | Read more »
Infinite Tanks (Games)
Infinite Tanks 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: | Read more »
Agatha Christie - The ABC Murders (FULL)...
Agatha Christie - The ABC Murders (FULL) 1.0 Device: iOS Universal Category: Games Price: $6.99, Version: 1.0 (iTunes) Description: Agatha Christie: The ABC Murders Your weapon is your knowledge. Your wits will be put to the ultimate... | Read more »
HeadlessD (Games)
HeadlessD 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: HeadlessD is hand-painted dungeon crawler with intuitive touch controls and NO in-app purchases. | Read more »
Leaf for Twitter (Social Networking)
Leaf for Twitter 1.0.1 Device: iOS iPhone Category: Social Networking Price: $4.99, Version: 1.0.1 (iTunes) Description: | Read more »
Banner Saga 2 (Games)
Banner Saga 2 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: The epic award winning story-based role-playing game continues its emotional journey across a breaking world. Lead your Viking... | Read more »
Concrete Jungle (Games)
Concrete Jungle 1.16 Device: iOS Universal Category: Games Price: $4.99, Version: 1.16 (iTunes) Description: A follow up to the puzzle hit 'MegaCity'! Concrete Jungle is a new take on the city building genre that swaps micro-... | Read more »
5 great apps for the budget traveller
Travelling abroad, or even within your home country, has never been easier thanks to our handy smartphone companions. There are hundreds of apps on the market that promise to make your world journeys hassle-free, but we've selected five of the... | Read more »
Zip—Zap (Games)
Zip—Zap 1.01 Device: iOS Universal Category: Games Price: $1.99, Version: 1.01 (iTunes) Description: Touch to contract.Release to let go.Bring the clumsy mechanical beings home. · · · over 100 levelsno adsno in-app-purchases Zip—... | Read more »

Price Scanner via MacPrices.net

Apple refurbished Mac minis available startin...
Apple has Certified Refurbished Mac minis available starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: - 1.4GHz Mac mini: $419 $80 off MSRP - 2.6GHz Mac... Read more
13-inch 2.5GHz MacBook Pro available for $928...
Overstock has the 13″ 2.5GHz MacBook Pro available for $927.99 including free shipping. Their price is $171 off MSRP. Read more
Buying McLaren Would Give Apple Instant Car C...
Apple “iCar” rumors have waxed and waned over the years, piquing interest and speculation as to whether Apple is seriously interested in getting into the automotobile business, either in a joint... Read more
Aetna to Transform Members’ Consumer Health E...
Health care benefits company Aetna, which has an estimated 46.3 million clients, today announced a new initiative to revolutionize members consumer health experience by combining the power of iOS... Read more
USB-IF Announces USB Audio Device Class 3.0 S...
USB Implementers Forum (USB-IF), the support organization for the advancement and adoption of USB technology, today announced the USB Audio Device Class 3.0 specification to establish USB Audio over... Read more
Clearance 12-inch 1.2GHz Retina MacBooks, App...
Apple has Certified Refurbished 2015 12″ 1.2GHz Retina MacBooks available for $1189, or $410 off original MSRP. Apple will include a standard one-year warranty with each MacBook, and shipping is free... Read more
Logitech SmartDock and Skype For Business Com...
Logitech has announced Logitech SmartDock, an AV meeting room solution designed in collaboration with Microsoft. Logitech SmartDock works with Skype for Business and qualified devices, including... Read more
27-inch iMacs on sale for up to $220 off MSRP
B&H Photo has 27″ Apple iMacs on sale for up to $200 off MSRP including free shipping plus NY sales tax only: - 27″ 3.3GHz iMac 5K: $2099 $200 off MSRP - 27″ 3.2GHz/1TB Fusion iMac 5K: $1899.99 $... Read more
Apple Macs and iPads available for up to $300...
Purchase a new Mac or iPad using Apple’s Education Store and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free, and... Read more
Save up to $600 with Apple refurbished Mac Pr...
Apple has Certified Refurbished Mac Pros available 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 following... Read more

Jobs Board

*Apple* Retail - Multiple Positions- Chicago...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions- Raleigh...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
User Support Specialist *Apple* Product Spe...
…Description:Ciber, Inc. is seeking a User Support Specialist - Apple Product Support in Nashville, TN!Responsibilities:Support, implementation, and upgrade of Read more
Restaurant Manager (Neighborhood Captain) - A...
…in every aspect of daily operation. WHY YOU'LL LIKE IT: You'll be the Big Apple . You'll solve problems. You'll get to show your ability to handle the stress and Read more
US- *Apple* Store Leader Program - Apple (Un...
…Summary Learn and grow as you explore the art of leadership at the Apple Store. You'll master our retail business inside and out through training, hands-on Read more
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