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Jul 98 Prog Challenge

Volume Number: 14 (1998)
Issue Number: 7
Column Tag: Programmer's Challenge

Jul 97 Programmer's Challenge

by Bob Boonstra, Westford, MA

Going Up?

Welcome to the Programmer's Challenge Skyscraper. Your Challenge this month is to assume control of our skyscraper's elevators and efficiently move a dedicated crew of simulated employees up and down the building.

The prototype for the code you should write is:

#if defined(__cplusplus)
extern "C" {
#endif

#define kMaxFloors 500
#define kMaxElevators 100
#define kElevatorCapacity 16

typedef enum {         /* commanded action for elevator car */
  kGoingUp=1,          /* send car up one floor */
  kGoingDown,          /* send car down one floor */
  kStoppedGoingUp,     /* stop car at an intermediate floor, car going up */
  kStoppedGoingDown,   /* stop car at an intermediate floor, car going down */
  kStoppedIdle         /* stop car, car in idle state */
} CarAction;

typedef struct CarState {
  long atFloor;        /* current location of car */
  long goingToFloor[kMaxFloors];
    /* goingToFloor[i] is the number of passengers in the car is going to floor [i] */
 } CarState;

typedef Boolean (*AdvanceTimeProc) (
                      /* return value of TRUE means Elevator should exit */
  CarAction action[kMaxElevators],  /* direction you move each elevator */
  CarState newState[kMaxElevators],  /* returns new state of each elevator */
  Boolean stopsAtFloor[kMaxFloors],
     /* stopsAtFloor[i]==TRUE means elevator stops at floor i */
  Boolean callGoingUp[kMaxFloors], 
     /* callGoingUp[i]==TRUE means a passenger on floor i wants to go up */
  Boolean callGoingDown[kMaxFloors]
     /* callGoingDown[i]==TRUE means a passenger on floor i wants to go down */
);

void Elevator(
  long numFloors,     /* number of floors in our building, < kMaxFloors */
  long numElevators,  /* number of elevators in our building, <
                         kMaxElevators */
  AdvanceTimeProc AdvanceTime  /* callback to get new state */
);
#if defined(__cplusplus)
}
#endif

Your Elevator routine will be called with the number of floors (numFloors) in our simulated skyscraper, the number of elevators (numElevators) at your command, and a callback routine (AdvanceTime). You should repeatedly call AdvanceTime, commanding an action and a set of constraints (stopsAtFloor) for each elevator car and receiving back the newState of each car. AdvanceTime will also provide an indicator of whether any prospective passengers on floor i have called an elevator to take them higher (callGoingUp[i]) or lower (callGoingDown[i]).

The newState returned by AdvanceTime provides the location of each car and the number of occupants. atFloor is the floor at which the car is now located. Our elevator passengers are extraordinarily cooperative -- on entering, they all indicate their destination by pressing the button corresponding to their floor, whether or not that floor has already been selected, allowing AdvanceTime to give you an accurate count of the passengers going to floor i (goingToFloor[i]). Our passengers are also extraordinarily swift --they exit and enter in such an orderly fashion that the passenger exchange takes place in one time step.

Each call to AdvanceTime will move all the elevators one floor in the direction you indicate. If you stop the car by setting action to kStoppedGoingUp, kStoppedGoingDown, or kStoppedIdle, passengers headed for the current floor will exit and new passengers, up to kElevatorCapacity, will enter. Almost always, passengers headed to higher (or lower) floors will only enter elevators that are kStoppedGoingUp (kStoppedGoingDown) or kStoppedIdle, but occasionally someone will be confused and enter an elevator headed in the wrong direction.

You are free to run your elevators anyway you see fit, except that a car declared to be kGoingUp (or kGoingDown) needs to continue going up (or down) until all passengers headed in that direction have exited. You can designate elevators to be express elevators by setting stopsAtFloor[i] to be FALSE for floors where this elevator does not stop. Passengers will only enter cars that will stop at their intended destination. You can change the stopsAtFloor values at any time, but you need to be careful not to strand passengers -- you can command the car to stop at any time, but the door will only open at floor i if stopsAtFloor[i] is TRUE.

The objective of this Challenge is to deliver passengers to their destinations as expeditiously as possible. You incur a cost of one point for each passenger for each time step from the time s/he presses the call button until the time s/he exits the elevator. You also incur one point for each 10 milliseconds of execution time, including the time spent by AdvanceTime. Stranding a passenger inside an elevator or not responding to an elevator call button results in disqualification of your solution. The solution that incurs the fewest points wins the Challenge. There are no storage constraints for this Challenge, except that it must execute on my 96MB 8500/200.

The Challenge will simulate a normal workday in our simulated skyscraper. People arrive at the beginning of the day either by entering the parking garage at floor 0 or by walking into the main entrance at floor 1. They work in approximately equal numbers on floors 2 through numFloors-1. During the day, they move about the building as necessary. Somewhere in the middle of the day, most of them take a lunch break, either at the cafeteria on floor 2 or by leaving the building. Nearly everyone leaves the building at the end of the day. However, as advanced as our elevators are, they don't have a clock, so you'll have to establish your strategy without knowing the time of day.

This will be a native PowerPC Challenge, using the latest CodeWarrior environment. Solutions may be coded in C, C++, or Pascal. Ernst Munter wins two Challenge points for suggesting this problem, way back in November, 1996.

Three Months Ago Winner

Congratulations to Sebastian Maurer for submitting the winning entry to the April Mancala Challenge. Sebastian won a round-robin tournament whose object was to efficiently capture the most stones in a variant of the ancient game of Mancala. In our variant of the game, the number of bowls ranged from 8 to 32, instead of the traditional 14, and players were allowed to move in either the clockwise or counter-clockwise directions. Congratulations also to JG Heithcock, whose solution actually captured more stones than Sebastian's did, but used better than 50% more execution time to do so. Both of the top solutions used an alpha-beta minmax technique to identify the best move, but Sebastian's heuristic for pruning the tree, combined with the time penalty of one stone per 100ms of execution time, gave him the higher overall score. Sebastian gained a little extra efficiency by partitioning his code into two parallel versions, one for playing first and another for playing second.

Twelve people submitted Mancala solutions, and eleven of those solutions participated in the tournament. (One solution occasionally made illegal moves, so it was eliminated to avoid unevenly affecting the scores of the other players.) The tournament consisted of seven test cases, with board sizes of 8, 12, 16, 20, 24, 28, and 32 bowls. Each solution played against each other solution twice in each test case, once playing first, and once playing second. The top solutions all used some variant of the minmax algorithm, while the lower ranking solutions used simpler heuristics, like always favoring moves that dropped the last stone into their mancala.

The table below lists the results of the tournament, with the solutions ranked in order of total points earned. It lists total execution time for the tournament, the total number of stones captured, the solution rank if execution time had been ignored, total points earned, as well as code size, data size, and programming language used. As usual, 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.

NameTime (secs)Cum StonesRank (stones)Cum PointsCode SizeData SizeLang
Sebastian Maurer (10)54.1614764214222.403488136C
JG Heithcock85.3714897114043.26178448C++
Ken Krugler97.4514627313652.464288308C++
Randy Boring (73)59.9014055413456.028048824C
Eric Kenninga21.1013399513187.9914584894C++
Willeke Rieken (47)3.6311667611630.7440888C++
Simon Jensen-Fellows0.3311512711508.6833646147C, Res
Dennis Jones (10)2.7610383910355.412556125C++
Eric Hangstefer (9)0.05102521010251.543724124C
Ernst Munter (362)104.7611178810130.42791613C++
Josh Cooley0.279446119443.29222864C
K. H.0.00Errors120.003772104C++

Top Contestants

Here are the Top Contestants for the Programmer's Challenge, including everyone who has accumulated more than 10 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.

  1. Munter, Ernst 210 points
  2. Boring, Randy 70 points
  3. Cooper, Greg 61 points
  4. Mallett, Jeff 50 points
  5. Rieken, Willeke 47 points
  6. Nicolle, Ludovic 34 points
  7. Lewis, Peter 31 points
  8. Maurer, Sebastian 30 points
  9. Gregg, Xan 24 points
  10. Murphy, ACC 24 points
  11. Hart, Alan 21 points
  12. Antoniewicz, Andy 20 points
  13. Day, Mark 20 points
  14. Higgins, Charles 20 points
  15. Hostetter, Mat 20 points
  16. Studer, Thomas 20 points

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 Sebastian's winning solution to the Mancala Challenge:

Mancala.C
Copyright 1998, Sebastian M. Maurer

#include <stdio.h>
#include "Mancala.h"

enum { kDefault, kPlayAgain, kGameOver };
typedef long StateOfGame;

// There are two versions of almost every routine
// so we don't have to decide at run time
// which side to play on. It speeds things up a
// little bit
// AlphaBeta1 and AlphaBeta2 are the recursive searchers
// for each of the two players. They return the value of
// best move (returned in *chosenBowl, *chosenDirection).
// For a description of Minimax and Alphabeta searches,
// see Peter Norvig's
// "Paradigms of Artificial Intelligence Programming"

#define kMaxSignedLong    0x7FFFFFFF

Prototypes
long AlphaBeta1(
  long depth,
  long board[],
  long *boardStorage,
  const long boardSize,
  long *chosenBowl,
  long *chosenDirection,
  long lowerBound,
  /* any big negative number to enter recursion */
  long upperBound      
  /* any big positive number to enter recursion */
);

long AlphaBeta2(
  long depth,
  long board[],
  long *boardStorage,
  const long boardSize,
  long *chosenBowl,
  long *chosenDirection,
  long lowerBound,
  long upperBound
);

// DropStones -- play the move
// Return true if we get to play again

Boolean DropStones1(
  long board[],
  const long boardSize,
  long bowlPlayed,
  long directionPlayed
);

Boolean DropStones2(
  long board[],
  const long boardSize,
  long bowlPlayed,
  long directionPlayed
);

// SideEmpty returns true if the side is empty
// (and the game is over)

Boolean FirstSideEmpty(
  long board[],
  const long halfBoardSize
);

Boolean SecondSideEmpty(
  long board[],
  const long boardSize
);
// Moves all the remaining stones
// to the appropriate Mancala

void RemainingToMancala(
  long board[],
  const long boardSize,
  const Boolean playerOne
);

// DoMove Drops the stones, checks if the game
// is over (if so, cleans up the board), and
// returns kGameOver, kPlayAgain, or kDefault
StateOfGame DoMove1(
  long board[],
  const long boardSize,
  long bowlPlayed,
  long directionPlayed
);

StateOfGame DoMove2(
  long board[],
  const long boardSize,
  long bowlPlayed,
  long directionPlayed
);

// Called only once from
// within Mancala
Boolean ClaimingVictory(
  long board[],
  const long boardSize,
  const Boolean playerOne
);

Mancala
Boolean Mancala(        /* return true if claiming victory */
  long board[]          /* on entry, board[i] is number of stones in bowl i */
                      /* on exit, board reflects the results of your move */
  const long boardSize,  /* number of bowls in the board, including mancalas */
  void *privStorage,    /* pointer to 1MB of storage for your use */
  const Boolean newGame,  /* true for your first move of a game */
  const Boolean playerOne,  /* true when you are the first player */
  long *bowlPlayed,        /* return the number of the bowl you played from */
  long *directionPlayed    /* return 1 if you played counter-clockwise, */
                        /* return -1 if you played clockwise */
)
{
#pragma unused(newGame)
  // Q&D way to decide how far to search
  // so that we don't lose too much time
  long depth;
  switch (boardSize)
  {
    case 8: depth = 10; break;
    case 10: depth = 8; break;
    case 12:
    case 14: depth = 6; break;
    case 16: 
    case 18: depth = 5; break;
    case 20: 
    case 22: 
    case 24: 
    case 26: depth = 4; break;
    case 28: 
    case 30: 
    case 32: depth = 3; break;
    default: depth = 1; break;
  }

  // Start recursion and play move
  if (playerOne) {
    AlphaBeta1(depth, board, (long*)privStorage,
      boardSize, bowlPlayed, directionPlayed,
      -kMaxSignedLong, kMaxSignedLong);
    DropStones1(board, boardSize,
      *bowlPlayed, *directionPlayed);
  }
  else
  {
    AlphaBeta2(depth, board, (long*)privStorage,
      boardSize, bowlPlayed, directionPlayed,
      -kMaxSignedLong, kMaxSignedLong);
    DropStones2(board, boardSize,
      *bowlPlayed, *directionPlayed);
  }
  
  // Correct to proper convention
  *directionPlayed = - (*directionPlayed);
  return ClaimingVictory(board, boardSize, playerOne);
}

AlphaBeta1
long AlphaBeta1(
  long depth,
  long board[],
  long *boardStorage,
  const long boardSize,
  long *chosenBowl,
  long *chosenDirection,
  long lowerBound,
  long upperBound
)
{
  long myMancala, hisMancala, firstBowl, halfBoardSize;
  long bowl, dir, value, bestBowl, bestDir;
  long *workingBoard;
  
  halfBoardSize = boardSize / 2;
  workingBoard = boardStorage + depth * boardSize;
  myMancala = 0;
  hisMancala = halfBoardSize;
  firstBowl = 1;
  
  for (bowl = firstBowl; bowl < hisMancala; bowl++)
    if (board[bowl] > 0)
    {
      StateOfGame result;
      long i;

      dir = -1;

      // The following trick speeds the whole program
      // up by about 1 percent... take it or leave it
      for (i = 0; i < halfBoardSize; i++)
        ((double*)workingBoard)[i] =
          ((double*)board)[i];
        
      result = DoMove1(workingBoard, boardSize,
                bowl, dir);
      if ((depth == 0) || (result == kGameOver))
        value = workingBoard[myMancala] -
              workingBoard[hisMancala];
      else
      {
        if (result == kPlayAgain)
          value = AlphaBeta1(
                depth - 1, workingBoard,
                boardStorage, boardSize,
                chosenBowl, chosenDirection,
                lowerBound, upperBound);
        else
          value = - AlphaBeta2(
                depth - 1, workingBoard,
                boardStorage, boardSize,
                chosenBowl, chosenDirection,
                - upperBound, - lowerBound);
      }

      if (value > lowerBound)
      {
        bestBowl = bowl;
        bestDir = dir;
        lowerBound = value;
        
        if (lowerBound >= upperBound)
          break;
      }

      dir = 1;

      for (i = 0; i < halfBoardSize; i++)
        ((double*)workingBoard)[i] =
          ((double*)board)[i];
        
      result = DoMove1(workingBoard, boardSize, bowl, dir);
      if ((depth == 0) || (result == kGameOver))
        value = workingBoard[myMancala] -                   workingBoard[hisMancala];
      else
      {
        if (result == kPlayAgain)
          value = AlphaBeta1(
                depth - 1, workingBoard,
                boardStorage, boardSize,
                chosenBowl, chosenDirection,
                lowerBound, upperBound);
        else
          value = - AlphaBeta2(
                depth - 1, workingBoard,
                boardStorage, boardSize,
                chosenBowl, chosenDirection,
                - upperBound, - lowerBound);
      }

      if (value > lowerBound)
      {
        bestBowl = bowl;
        bestDir = dir;
        lowerBound = value;
        
        if (lowerBound >= upperBound)
          break;
      }
      
    }
  
  *chosenBowl = bestBowl;
  *chosenDirection = bestDir;
  return lowerBound;
}

AlphaBeta2
long AlphaBeta2(
  long depth,
  long board[],
  long *boardStorage,
  const long boardSize,
  long *chosenBowl,
  long *chosenDirection,
  long lowerBound,
  long upperBound
)
{
  long myMancala, hisMancala, firstBowl, halfBoardSize;
  long bowl, dir, value, bestBowl, bestDir;
  long *workingBoard;
  
  halfBoardSize = boardSize / 2;

  workingBoard = boardStorage + depth * boardSize;
  myMancala = halfBoardSize;
  hisMancala = 0;
  firstBowl = myMancala + 1;
  for (bowl = firstBowl; bowl < boardSize; bowl++)
    if (board[bowl] > 0)
    {
      long i, result;

      dir = -1;

      for (i = 0; i < halfBoardSize; i++)
        ((double*)workingBoard)[i] =
          ((double*)board)[i];
      
      result = DoMove2(workingBoard, boardSize,
                bowl, dir);
    if ((depth == 0) || (result == kGameOver))
        value = workingBoard[myMancala] -
              workingBoard[hisMancala];
      else
      {
        if (result == kPlayAgain)
          value = AlphaBeta2(
                depth - 1, workingBoard,
                boardStorage, boardSize,
                chosenBowl, chosenDirection,
                lowerBound, upperBound);
        else
          value = - AlphaBeta1(
                depth - 1, workingBoard,
                boardStorage, boardSize,
                chosenBowl, chosenDirection,
                - upperBound, - lowerBound);
      }
      if (value > lowerBound)
      {
        bestBowl = bowl;
        bestDir = dir;
        lowerBound = value;
        if (lowerBound >= upperBound)
          break;
      }
      
      dir = 1;
      
      for (i = 0; i < halfBoardSize; i++)
        ((double*)workingBoard)[i] =
          ((double*)board)[i];

      result = DoMove2(workingBoard, boardSize,
                bowl, dir);
      if ((depth == 0) || (result == kGameOver))
        value = workingBoard[myMancala] -
              workingBoard[hisMancala];
      else
      {
        if (result == kPlayAgain)
          value = AlphaBeta2(
                depth - 1, workingBoard,
                boardStorage, boardSize,
                chosenBowl, chosenDirection,
                lowerBound, upperBound);
        else
          value = - AlphaBeta1(
                depth - 1, workingBoard,
                boardStorage, boardSize,
                chosenBowl, chosenDirection,
                - upperBound, - lowerBound);
      }

      if (value > lowerBound)
      {
        bestBowl = bowl;
        bestDir = dir;
        lowerBound = value;
        if (lowerBound >= upperBound)
          break;
      }

    }
  
  *chosenBowl = bestBowl;
  *chosenDirection = bestDir;
  return lowerBound;
}

DropStones1
/***
Boolean DropStones()
Drops stones, return true if we get to play again
***/

inline Boolean DropStones1(
  long board[],
  const long boardSize,
  long bowlPlayed,
  long directionPlayed
)
{
  long myMancala, hisMancala, firstBowl, lastBowl;
  long stonesInHand, nextBowl;

  myMancala = 0;
  hisMancala = boardSize / 2;
  firstBowl = 1;
  lastBowl = hisMancala - 1;

  stonesInHand = board[bowlPlayed];
  board[bowlPlayed] = 0;
  nextBowl = bowlPlayed;
  /* Drop stones */
  while (stonesInHand > 0) {
    nextBowl += directionPlayed;
    
    if (nextBowl == hisMancala)
      nextBowl += directionPlayed;
    else
    {
      if (nextBowl < 0)
        nextBowl = boardSize - 1;
      else
        if (nextBowl == boardSize)
          nextBowl = 0;
    }
    board[nextBowl] += 1;
    stonesInHand -= 1;
  }
  
  /* Perform capture */
  if ((board[nextBowl] == 1) &&
    (nextBowl >= firstBowl) &&
    (nextBowl <= lastBowl))
  {
    board[nextBowl] = 0;
    board[myMancala] += 
      (1 + board[boardSize - nextBowl]);
    board[boardSize - nextBowl] = 0;
  }
  
  /* Return true if get to play again */
  return (nextBowl == myMancala);
}

DropStones2
inline Boolean DropStones2(
  long board[],
  const long boardSize,
  long bowlPlayed,
  long directionPlayed
)
{
  long myMancala, firstBowl, lastBowl;
  long stonesInHand, nextBowl;

  myMancala = boardSize / 2;
  firstBowl = myMancala + 1;
  lastBowl = boardSize - 1;

  stonesInHand = board[bowlPlayed];
  board[bowlPlayed] = 0;
  nextBowl = bowlPlayed;
  /* Drop stones */
  while (stonesInHand > 0) {
    nextBowl += directionPlayed;
    
    if (nextBowl <= 0)
      nextBowl = boardSize - 1;
    else
      if (nextBowl == boardSize)
        nextBowl = 1;
    board[nextBowl] += 1;
    stonesInHand -= 1;
  }
  
  /* Perform capture */
  if ((board[nextBowl] == 1) &&
    (nextBowl >= firstBowl) &&
    (nextBowl <= lastBowl))
  {
    board[nextBowl] = 0;
    board[myMancala] +=
      (1 + board[boardSize - nextBowl]);
    board[boardSize - nextBowl] = 0;
  }
  
  /* Return true if get to play again */
  return (nextBowl == myMancala);
}

FirstSideEmpty
/*
Boolean FirstSideEmpty()
Checks to see if first side has no stones left in it
*/
inline Boolean FirstSideEmpty(
  long board[],
  const long halfBoardSize
) 
{
  long bowl;
  for(bowl = halfBoardSize - 1; bowl > 0; bowl--)
    if (board[bowl] != 0)
      return false;
  return true;
}


SecondSideEmpty
/*
Boolean SecondSideEmpty()
Checks to see if first side has no stones left in it
*/
inline Boolean SecondSideEmpty(
  long board[],
  const long boardSize
) 
{
  long bowl;
  long halfBoardSize = boardSize / 2;
  for(bowl = boardSize - 1; bowl > halfBoardSize; bowl--)
    if (board[bowl] != 0)
      return false;
  return true;
}

RemainingToMancala
/*
void RemainingToMancala()
Moves remaining stones on specified side into Mancala
*/
inline void RemainingToMancala(
  long board[],
  const long boardSize,
  const Boolean playerOne
)
{
  long mancala, firstBowl, lastBowl, bowl;

  if (playerOne) {
    mancala = 0;
    firstBowl = 1;
    lastBowl = boardSize / 2 - 1;
  } else {
    mancala = boardSize / 2;
    firstBowl = boardSize / 2 + 1;
    lastBowl = boardSize - 1;
  }  
  
  for(bowl = firstBowl; bowl <= lastBowl; bowl++)
  {
    board[mancala] += board[bowl];
    board[bowl] = 0;
  }
}


DoMove1
/***
StateOfGame DoMove()
Drops the specified stones and cleans up the board 
if the game is over.
***/

inline StateOfGame DoMove1(
  long board[],
  const long boardSize,
  long bowlPlayed,
  long directionPlayed
)
{
  Boolean getToPlayAgain;

  getToPlayAgain = DropStones1(board, boardSize,
            bowlPlayed, directionPlayed);

  if (FirstSideEmpty(board, boardSize / 2)) {
    RemainingToMancala(board, boardSize, false);
    return kGameOver;
  }
  
  if (SecondSideEmpty(board, boardSize)) {
    RemainingToMancala(board, boardSize, true);
    return kGameOver;
  }
  
  if (getToPlayAgain)
    return kPlayAgain;
  else
    return kDefault;
}

DoMove2
inline StateOfGame DoMove2(
  long board[],
  const long boardSize,
  long bowlPlayed,
  long directionPlayed
)
{
  Boolean getToPlayAgain;
  
  getToPlayAgain = DropStones2(board, boardSize,
            bowlPlayed, directionPlayed);

  if (FirstSideEmpty(board, boardSize / 2)) {
    RemainingToMancala(board, boardSize, false);
    return kGameOver;
  }
  
  if (SecondSideEmpty(board, boardSize)) {
    RemainingToMancala(board, boardSize, true);
    return kGameOver;
  }
  
  if (getToPlayAgain)
    return kPlayAgain;
  else
    return kDefault;
}

ClaimingVictory
/* Boolean ClaimingVictory()
  Only called before returning from Mancala
  Does not clean up the board
*/
Boolean ClaimingVictory(
  long board[],
  const long boardSize,
  const Boolean playerOne
)
{
  long bowl;
  long sum = 0;
  long halfBoardSize = boardSize / 2;
  
  if (FirstSideEmpty(board, halfBoardSize))
  {
    for (bowl = halfBoardSize + 1;
        bowl < boardSize; bowl++)
      sum += board[bowl];
    if (playerOne)
      return board[0] > (sum + board[halfBoardSize]);
    else
      return board[0] < (sum + board[halfBoardSize]);
  }
  if (SecondSideEmpty(board, boardSize))
  {
    for (bowl = 1; bowl < halfBoardSize; bowl++)
      sum += board[bowl];
    if (playerOne)
      return (board[0] + sum) > board[halfBoardSize];
    else
      return (board[0] + sum) < board[halfBoardSize];
  }
  return false;
}
 

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Firefox 78.0.1 - Fast, safe Web browser.
Firefox offers a fast, safe Web browsing experience. Browse quickly, securely, and effortlessly. With its industry-leading features, Firefox is the choice of Web development professionals and casual... Read more
BetterTouchTool 3.389 - Customize multi-...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom)... Read more
Slack 4.7.0 - Collaborative communicatio...
Slack brings team communication and collaboration into one place so you can get more work done, whether you belong to a large enterprise or a small business. Check off your to-do list and move your... Read more
OsiriX Lite 11.0.3 - 3D medical image pr...
OsiriX Lite is an image processing software dedicated to DICOM images (".dcm" / ".DCM" extension) produced by medical equipment (MRI, CT, PET, PET-CT, ...) and confocal microscopy (LSM and BioRAD-PIC... Read more
Wireshark 3.2.5 - Network protocol analy...
Wireshark is one of the world's foremost network protocol analyzers, and is the standard in many parts of the industry. It is the continuation of a project that started in 1998. Hundreds of... Read more
Dabble 1.6.1 - Organize your manuscript,...
Dabble organizes your manuscript, story notes, and plot. Dabble simplifies the story, leaving more room in your brain to create, which is what being a writer is really about. Organize your story.... Read more

Latest Forum Discussions

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Pokemon Go's July Community Day wil...
Pokemon Go developers have announced the details concerning the upcoming Gastly Community Day. This particular event was selected by the players of the game after the Gas Pokemon came in second place after a poll that decided which Pokemon would... | Read more »
Clash Royale: The Road to Legendary Aren...
Supercell recently celebrated its 10th anniversary and their best title, Clash Royale, is as good as it's ever been. Even for lapsed players, returning to the game is as easy as can be. If you want to join us in picking the game back up, we've put... | Read more »
Detective Di is a point-and-click murder...
Detective Di is a point-and-click murder mystery set in Tang Dynasty-era China. You'll take on the role of China's best-known investigator, Di Renjie, as he solves a series of grisly murders that will ultimately lead him on a collision course with... | Read more »
Dissidia Final Fantasy Opera Omnia is se...
Dissidia Final Fantasy Opera Omnia, one of Square Enix's many popular mobile RPGs, has announced a plethora of in-game events that are set to take place over the summer. This will include several rewards, Free Multi Draws and more. [Read more] | Read more »
Sphaze is a neat-looking puzzler where y...
Sphaze is a neat-looking puzzler where you'll work to guide robots through increasingly elaborate mazes. It's set in a visually distinct world that's equal parts fantasy and sci-fi, and it's finally launched today for iOS and Android devices. [... | Read more »
Apple Arcade is in trouble
Yesterday, Bloomberg reported that Apple is disappointed in the performance of Apple Arcade and will be shifting their approach to the service by focusing on games that can retain subscribers and canceling other upcoming releases that don't fit... | Read more »
Pixel Petz, an inventive platform for de...
Pixel Petz has built up a sizeable player base thanks to its layered, easy-to-understand creative tools and friendly social experience. It revolves around designing, trading, and playing with a unique collection of pixel art pets, and it's out now... | Read more »
The King of Fighters Allstar's late...
The King of Fighters ALLSTAR, Netmarble's popular action RPG, has once again been updated with a plethora of new content. This includes battle cards, events and 21 new fighters, which increases the already sizeable roster even more. [Read more] | Read more »
Romancing SaGa Re;univerSe, the mobile s...
Square Enix latest mobile spin-off Romancing SaGa Re;univerSe is available now globally for both iOS and Android. It initially launched in Japan back in 2018 where it's proven to be incredibly popular, so now folks in the West can finally see what... | Read more »
Away: Journey to the Unexpected is a sto...
Away: Journey to the Unexpected looks really quite lovely. Stylish, cute, and clearly heavily inspired by Japanese animation, it's amongst the best-looking mobile games on the horizon. Developed by a two-person team, this story-driven rogue-lite... | Read more »

Price Scanner via MacPrices.net

July 4th Sale: Woot offers wide range of Macs...
Amazon-owned Woot is blowing out a wide range of Apple Macs and iPads for July 4th staring at $279 and ranging up to just over $1000. Models vary from older iPads and 11″ MacBook Airs to some newer... Read more
Apple Pro Display XDR with Nano-Texture Glass...
Abt Electronics has Apple’s new 32″ Pro Display XDR model with the nano-texture glass in stock and on sale today for up to $144 off MSRP. Shipping is free: – Pro Display XDR (nano-texture glass): $... Read more
New 2020 Mac mini on sale for up to $100 off...
Amazon has Apple’s new 2020 Mac minis on sale today for $40-$100 off MSRP with prices starting at $759. Shipping is free: – 2020 4-Core Mac mini: $759 $40 off MSRP – 2020 6-Core Mac mini: $998.99 $... Read more
July 4th Sale: $100 off every 2020 13″ MacBoo...
Apple resellers have new 2020 13″ MacBook Airs on sale for $100 off Apple’s MSRP as part of their July 4th sales. Starting at $899, these are the cheapest new 2020 MacBooks for sale anywhere: (1) B... Read more
This hidden deal on Apple’s site can save you...
Are you a local, state, or federal government employee? If so, Apple offers special government pricing on their products, including AirPods, for you as well as immediate family members. Here’s how... Read more
Apple Watch Series 3 models on sale for new l...
Amazon has Apple Watch Series 3 GPS models on sale for $30 off MSRP, starting at only $169. Their prices are the lowest available for these models from any Apple reseller. Choose Amazon as the seller... Read more
Deal Alert! Get these refurbished 2018 13″ Ma...
Apple has restocked and lowered prices on select Certified Refurbished 2018 13″ MacBook Airs, starting at only $679. Each MacBook features a new outer case, comes with a standard Apple one-year... Read more
July 4th Sale: 13″ 2.0GHz MacBook Pros for $2...
B&H Photo has new 2020 13″ 2.0GHz MacBook Pros on sale for $200 off Apple’s MSRP as part of their July 4th sale. Prices start at $1599. These are the same MacBook Pros sold by Apple in their... Read more
July 1 only: $100 off Apple iPhone 11, 11 Pro...
Boost Mobile is offering Apple iPhone 11, 11 Pro, and iPhone 11 Pro Max models for $100 off MSRP with service. Their discount reduces the cost of an iPhone 11/64GB to $599, iPhone 11 Pro to $899 for... Read more
Apple offers $50-$100 Education discount on i...
Purchase a new 12.9″ or 11″ iPad Pro at Apple using your Education discount, and Apple will take $50-$100 off their MSRP. All teachers, students, and staff of any educational institution with a .edu... Read more

Jobs Board

Operating Room Assistant, *Apple* Hill Surg...
Operating Room Assistant, Apple Hill Surgical Center - Full Time, Day Shift, Monday - Saturday availability required Tracking Code 62363 Job Description Operating Read more
Perioperative RN - ( *Apple* Hill Surgical C...
Perioperative RN - ( Apple Hill Surgical Center) Tracking Code 60593 Job Description Monday - Friday - Full Time Days Possible Saturdays General Summary: Under the Read more
Product Manager, *Apple* Commercial Sales -...
Product Manager, Apple Commercial Sales Austin, TX, US Requisition Number:77652 As an Apple Product Manager for the Commercial Sales team at Insight, you Read more
*Apple* Mac Product Engineer - Barclays (Uni...
Apple Mac EngineerWhippany, NJ Support the development and delivery of solutions, products, and capabilities into the Barclays environment working across technical Read more
Blue *Apple* Cafe Student Worker - Pennsylv...
…enhance your work experience. Student positions are available at the Blue Apple Cafe. Employee meal discount during working hours. Duties include food preparation, Read more
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