TweetFollow Us on Twitter

Jun 98 Prog Challenge

Volume Number: 14 (1998)
Issue Number: 6
Column Tag: Programmer's Challenge

June 1998 Programmers Challenge

by Bob Boonstra, Westford, MA

Blackjack

This month we welcome you to the Programmer's Challenge Casino, grease your palm with 1000 Programmer's Challenge Credits (not to be confused with Challenge points) furnished by the house, and invite you to spend a few milliseconds at our Challenge Blackjack table.

The prototype for the code you should write is:

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

#pragma enumsalwaysint on

typedef enum {kHiddenSuit=0,kClub,kDiamond,kHeart,kSpade} Suit;
typedef enum { kHiddenSpot=0,
 kAce,k1,k2,k3,k4,k5,k6,k7,k8,k9,k10,kJack,kQueen,kKing
} Spot;

typedef struct Card {  /* suit and spots for a card */
 Suit suit;
 Spot spot;
} Card;

typedef enum {
 kStandPat=0,          /* no more cards for this hand */
 kClaimBlackjack,      /* if your initial cards are Ace and a face card */
    /* the following values request another card */
 kSplitAndHitMe,       /* only valid with initial pair showing */
 kHitMe,               /* request another card for this hand */
    /* the following values request one more card */
 kDoubleDownAndHitMe   /* only valid with initial two cards */
} Action;

typedef enum {         /* results of your request for a card */
    /* this result is possible anytime after a rule violation */
 kIllegalPlay=-1,      /* illegal play causes loss of your bet */
    /* these results are possible after you request another card */
 kNoResult=0,          /* play again if you like */
 kYouWin5CardCharlie,  /* you have five cards and do not bust, you win */
 kYouBust,             /* your card puts you over 21, you lose */
    /* this result is only possible after you kClaimBlackjack in the initial callback */
 kYouWinBlackjack,     /* you have Blackjack and dealer does not, you win */
    /* this result is only possible after initial callback for a game */
  kDealerWinsBlackjack,
    /* dealer has Blackjack, you do not, no card dealt, you lose */
    /* these results are possible after you kStandPat or kClaimBlackjack */
 kPush,                /* dealer has same score, no win or loss */
    /* these results are possible after you kStandPat */
 kDealerBusts,         /* dealer went over 21, you win */
 kDealerWinsHiTotal,   /* dealer has lower total, you lose */
 kYouWinHiTotal        /* you have lower total, you win */
} Result;

typedef void BetProc(     /* place a bet for this */
 unsigned int betAmount, 
    /* amount you bet, must be >= minBet and <= maxBet */
 Card yourHand[2],      /* your initial hand */ 
 Card dealerHand[2]    /* dealers initial hand, first card is hidden */
);

typedef Result HitProc(  /* returns result for this hand */
 Action yourAction,      /* hit me or not, split or not after initial pair, */
    /* double down or not after initial two cards */
 Boolean insurance,      /* TRUE requests insurance when eligible */
    /* these items are always returned */
 Card yourCards[],       /* all of your cards, including a new hit */
 int *numYourCards,      /* number of cards in yourCards */
    /* these items are returned when result is not kNoResult */
 Card dealerCards[],     /* dealers hand, with hidden card revealed */
    /* (helps with card counting) */ 
 int *numDealerCards,    /* number of cards in dealers hand */
 int *yourWinnings       /* winnings are positive, loss is negative */
);

void InitBlackjack(
 int numDecks,          /* number of decks used by the dealer, 2..10*/
 int yourBankroll,      /* number of credits you have to start */
 int minBet,            /* minimum bet for each hand */
 int maxBet,            /* maximum bet for each hand */
 BetProc makeABet,      /* callback to place a wager */
 HitProc hitMe          /* callback to get a card */
);

Boolean Blackjack(      /* return true to keep playing, false to cash in */
  Boolean newDeck       /* true when dealer starts with fresh numDecks decks of cards */
);

#if defined (__cplusplus)
}
#endif

Play at the Challenge Casino begins with a call to InitBlackjack, where you are told how many decks the house uses (numDecks), how many Credits you have to work with (yourBankroll) courtesy of the house, the minimum (minBet) / maximum (maxBet) bet per hand at the Casino, how to place a bet (the makeABet callback) and how ask for another card (the hitMe callback). Business is slow at the Casino, and you are the only player at the table.

After the call to InitBlackjack, your Blackjack routine will be called repeatedly until you run out of Credits (in which case we show you the door) or until you decide to cash in. The house is certain that you are not a card counter, so they make it very obvious when they are starting with a fresh set of numDecks decks of cards by setting the newDeck parameter.

The first thing your Blackjack routine should do is call the makeABet callback to make a wager and obtain your first cards. The dealer also receives two cards, one of which you can see and one of which is face down (kHiddenSuit and kHiddenSpot). The dealer's hidden card will be revealed to you only at the end of the hand. After you get your cards, you can repeatedly request an additional card by calling hitMe with yourAction set to kHitMe until you believe you will win the hand or you bust. Another card will be added to yourCards and *numYourCards will be incremented. You win at Blackjack by obtaining a hand total that is less than or equal to 21 and at the same time is higher than the total in the dealer's hand. Cards are counted at their face value (i.e., (int)theCard.spot), except for aces and picture cards (Jacks, Queens, Kings). Picture cards are counted with a value of 10. Aces can be counted as either 1 or 11, at the option of the player. (In our game, the hitMe routine will score Aces to your best advantage, giving you the highest possible hand total without exceeding 21.)

As long as your card total does not exceed 21, hitMe will return kNoResult and you may keep playing. If your total exceeds 21, hitMe will return kYouBust, in which case you lose regardless of what the dealer holds. If you draw a fifth card without going bust, you have a Five Card Charlie, hitMe returns kYouWin5CardCharlie, and you win.

When you are finished requesting additional cards, you should call hitMe with yourAction set to kStandPat. The dealer will then draw cards until s/he has a total of 17 or more, and hitMe will return kDealerBusts if the dealer's total exceeds 21, kDealerWinsHiTotal if the dealer's total is greater than yours, kYouWinHiTotal if your total is greater than the dealer's, or kPush if your total and the dealer's are the same. In addition, *yourWinnings is set to the net change in yourBankroll. In the case of a tie, or 'push', *yourWinnings is set to zero. In all cases, the dealer's full hand is provided in dealerHand once the result of the hand is determined, and *numDealerCards is set to the number of entries in dealerHand.

If your first two cards are an ace and a 10-valued card (a ten or a face card), you should call hitMe with yourAction set to kClaimBlackjack and hitMe will return with kYouWinBlackjack (unless the dealer also has a blackjack). If the dealer's first two cards are an ace and a 10-valued card, the dealer has a blackjack and hitMe will return kDealerWinsBlackjack, unless both you and the dealer have a blackjack, in which case the result is kPush. No additional cards are dealt when either player has blackjack.

You have the option of 'doubling down' after looking at your first two cards by calling hitMe with yourAction set to kDoubleDownAndHitMe. The hitMe routine will double your bet, give you one more card, play the dealer's hand, and return the result.

If your first two cards are identical in value, you may 'split' the hand and play each card separately. You do this by calling hitMe with yourAction set to kSplitAndHitMe. Play the first hand as usual, but instead of returning when the hand is finished, call hitMe with yourAction set to kSplitAndHitMe again to play the second hand. You may only split on the initial two cards, not on any subsequent pairs. You cannot double down on a split hand.

When the dealer's exposed card is an ace, you are allowed to request insurance of one half of your original bet. If the dealer has a blackjack, insurance protects you from losing your initial bet (i.e., your net winnings are zero). If the dealer does not have blackjack, you lose the insurance amount and win or lose the initial bet based on how the hand plays out.

Oh, and for those of you that think gambling doesn't pay, we must insist that you actually wager those Challenge Credits initially provided by the house. Your point total will be reduced by a 'freeloader penalty', the number of your initial yourBankroll of Credits that you fail to wager. Once you have wagered yourBankroll credits, you are free to continue playing or retire with your remaining funds without penalty.

The Challenge winner will be the player that accumulates the most points, where:

Points = Credits at game end ñ milliseconds played ñ freeloader penalty

This will be a native PowerPC Challenge, using the CodeWarrior environment. Solutions may be coded in C, C++, or Pascal.

Three Months Ago Winner

The March Challenge was to efficiently identify a sequence of airline flights that would take one from an origin to a destination in the minimum elapsed time, coping with the uncertainties of airline travel. Congratulations to Willeke Rieken (the Netherlands) taking first place in the Help Peter Get Home Challenge. Willeke won based on having fewer violations of the minimum connection time constraint specified in the problem statement, which resulted in less penalty time being added to his solution.

The winning solution is a little tough to read because Willeke apparently likes to be frugal with commentary. He begins by building what he calls a 'forest' of Departure records that associate each airline flight with the departure and arrival airport records. The work is then done by the FlyHome method of the Airp class instance associated with the departure airport. FlyHome then calls CalcExpectedTime for prospective intermediate stops, which in turn calls CalcExpectedTime for subsequent intermediate stops, eliminating dead ends and flights that result in loops. When the presumed fastest route is found, the JumpOnAPlane method is called to actually commit to taking the first flight segment, after which FlyHome is called for the intermediate airport to repeat the process with the intermediate airport as the departure point.

I used 12 random test cases to evaluate the solutions. The test cases resulted in between 1 and 5 flight segments per case, for a total of ~40 flight segments. I had hoped to use a digital version of the international airline guide to evaluate the solutions, but I was unable to obtain the guide until the last minute, and unable to reverse engineer the data structures in the time remaining. I was able to reverse engineer the flight schedule used on the Air Canada web site, containing the Air Canada flight database and a significant number of connecting flights from other airlines. I supplemented this with selected flights entered manually from a hardcopy of the international OAG, along with some arbitrary manual data. Note to self: sleep is a valuable thing ñ think more carefully about how you are going to test these Challenges in the future.

The table below shows the total flight time in hours for the 12 test, followed by the execution time in milliseconds, and the number of 24-hour penalties imposed for violating the connection time restriction imposed by the problem statement. The execution time, weighted so that one second of run time equates to one hour of simulated flight time, is added to the flight and penalty times to obtain the final score, with a lower score being better. Finally, the table lists the code size, data size, and programming language used for each of the solutions. The number in parentheses after a contestant's name is the total number of Challenge points earned in all Challenges to date prior to this one.

Name, Flight Time Execution (hours) Penalties (msecs) Score (24 hours) Code Data Lang
Willeke Rieken (27) 358.4 1159 1 383.6 3424 132 C++
Ernst Munter (352) 356.5 354 2 404.9 4164 1096 C++
Alan Hart (14) 414.8 995 2 463.8 5308 168 C++

Top 20 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 228
  2. Boring, Randy 73
  3. Cooper, Greg 61
  4. Mallett, Jeff 50
  5. Rieken, Willeke 47
  6. Nicolle, Ludovic 34
  7. Lewis, Peter 31
  8. Antoniewicz, Andy 24
  9. Gregg, Xan 24
  10. Murphy, ACC 24
  11. Hart, Alan 21
  12. Day, Mark 20
  13. Higgins, Charles 20
  14. Hostetter, Mat 20
  15. Studer, Thomas 20
  16. O'Connor, Turlough 14

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 solution to the Help Peter Get Home Challenge.

HelpPeter.Cp
Copyright 1998, Willeke Rieken

// FindQuickestRoute

#include "helppeter.h"

#include <stdlib.h>
#include <string.h>

#define kMinInADay 1440

class Airp;

class Departure
class Departure  // flights
{
  public:
    Airp  *fDestination;
    Departure  *fNextDep;
    long  fScheduledDepartureTime;  // minutes after midnight
    long  fExpectedFlightDuration;
    long  fTimeOffset;
    long  fFirstArrival;
    FlightNum  fFlightNumber;
    DayOfWeek  fFirstStartDay;
    Boolean  fOperatingDays[7];
    static  GetFlightTime fGetFlightTime;
    Departure(Flight *theFligth, long theTimeOffset,
              Airp *theArrAirp);
  void SetFirstArrival(DayOfWeek theStartDay, long theStartTime,
                          long theCumTime);
  long CalcExpectedTime(Airp *theEndAirp, long theFastestTime);
  long JumpOnAPlane(DayOfWeek theStartDay, long theStartTime,
                        Airp *theEndAirp);
};

class Airp
class Airp
{
  public:
    static Airp  **fAllAirports;
    static long  fNumAirports;
    Departure  *fFirstDep;
    long  fTimeOffset;
    long  fMinConnectTime;
    long  fFirstArrival;
    long  fPrevArrival;
    long  fPrevTime;
    short  fBeenHere;
    DayOfWeek  fPrevDay;
    Airp(Airport *theAirport);
    ~Airp();
    void AddFlight(Departure *theDep);
    void ResetFirstArrivals();
    long CalcExpectedTime(DayOfWeek theStartDay, 
                          long theStartTime,
                          Airp *theEndAirp, long theCumTime,
                          long theFastestTime);
    long FlyHome(DayOfWeek theStartDay, long theStartTime,
                  Airp *theEndAirp);
};

GetFlightTime Departure::fGetFlightTime = 0;

Departure::Departure
Departure::Departure(Flight *theFlight, long theTimeOffset, 
            Airp *theArrAirp)
{
  fDestination = theArrAirp;
  fNextDep = 0;
  strcpy(fFlightNumber, theFlight->flightNumber);
  fScheduledDepartureTime = 
      theFlight->scheduledDepartureTime.hour * 60 +
                    theFlight->scheduledDepartureTime.min;
  fExpectedFlightDuration = 
      theFlight->nominalFlightDuration.hour * 60 +
                    theFlight->nominalFlightDuration.min +
                    ((1 / theFlight->lambdaDeparture) +
                    (1 / theFlight->lambdaDuration) + 0.5);
  memcpy(fOperatingDays, theFlight->operatingDays, 7);
  fTimeOffset = theTimeOffset;
  fFirstArrival = 0x7fffffff;
}

Departure::SetFirstArrival
void Departure::SetFirstArrival(DayOfWeek theStartDay, 
        long theStartTime,  long theCumTime)
{
  long  aTime = theCumTime;
  
  // calculate time spent at the airport so Peter can eliminate
  // slower flights to the same airport
  if (fScheduledDepartureTime < theStartTime)
  {
    aTime = aTime + kMinInADay;
    if (theStartDay == Saturday)
      theStartDay = Sunday;
    else
      theStartDay = (DayOfWeek)(theStartDay + 1);
  }
  aTime = aTime + (fScheduledDepartureTime - theStartTime);
  while (!fOperatingDays[theStartDay])
  {
    aTime = aTime + kMinInADay;
    if (theStartDay == Saturday)
      theStartDay = Sunday;
    else
      theStartDay = (DayOfWeek)(theStartDay + 1);
  }
  aTime = aTime + fExpectedFlightDuration;
  fFirstArrival = aTime;
  fFirstStartDay = theStartDay;
  // store earliest arrival with the airport
  // Peter can eliminate slower flights from other airports
  if (aTime < fDestination->fFirstArrival)
    fDestination->fFirstArrival = aTime;
}

Departure::CalcExpectedTime
long Departure::CalcExpectedTime(Airp *theEndAirp, 
        long theFastestTime)
// theStartTime is local
{
  // the time is calculated in SetFirstArrival
  if (fDestination == theEndAirp)
  {
    return fFirstArrival;
  }
  else
  {
    if (fFirstArrival < theFastestTime)
    {
      // keep track of the day of the week
      DayOfWeek  aStartDay = fFirstStartDay;
      long  aStartTime = fScheduledDepartureTime + 
          fExpectedFlightDuration - fTimeOffset;

      if (aStartTime > kMinInADay)
      {
        aStartTime = aStartTime - kMinInADay;
        if (aStartDay == Saturday)
          aStartDay = Sunday;
        else
          aStartDay = (DayOfWeek)(aStartDay + 1);
      }
      else
        if (aStartTime < 0)
        {
          aStartTime = aStartTime + kMinInADay;
          if (aStartDay == Sunday)
            aStartDay = Saturday;
          else
            aStartDay = (DayOfWeek)(aStartDay - 1);
        }
      // calculate expected time to get home from the next airport
      long anExpectedTime = 
        fDestination->CalcExpectedTime(aStartDay, aStartTime, 
                theEndAirp, fFirstArrival, theFastestTime);
      if (anExpectedTime > 0)
        return fFirstArrival + anExpectedTime;
      else
        return anExpectedTime;  // slower or didn't arrive home
    }
    else
      return -1;  // slower
  }
}

Departure::JumpOnAPlane
long Departure::JumpOnAPlane(DayOfWeek theStartDay, long theStartTime, Airp *theEndAirp)
// theStartTime is local
{
  long  aTime = 0;
  long  aFlyingTime;
  
  // calculate time until the plane will depart
  if (fScheduledDepartureTime < theStartTime)
  {
    // tomorrow
    aTime = aTime + kMinInADay;
    if (theStartDay == Saturday)
      theStartDay = Sunday;
    else
      theStartDay = (DayOfWeek)(theStartDay + 1);
  }
  aTime = aTime + (fScheduledDepartureTime - theStartTime);
  while (!fOperatingDays[theStartDay])
  {
    aTime = aTime + kMinInADay;
    if (theStartDay == Saturday)
      theStartDay = Sunday;
    else
      theStartDay = (DayOfWeek)(theStartDay + 1);
  }
  // calculate delays and flying time
  aFlyingTime = (*fGetFlightTime)(fFlightNumber);
  aTime += aFlyingTime;
  if (fDestination == theEndAirp)
  {
    // Peter is home and won't take another plane
    return aTime;
  }
  else
  {
    // keep track of the day of the week
    theStartTime += aTime - fTimeOffset;
    if (theStartTime > kMinInADay)
    {
      theStartTime = theStartTime - kMinInADay;
      if (theStartDay == Saturday)
        theStartDay = Sunday;
      else
        theStartDay = (DayOfWeek)(theStartDay + 1);
    }
    else
      if (theStartTime < 0)
      {
        theStartTime = theStartTime + kMinInADay;
        if (theStartDay == Sunday)
          theStartDay = Saturday;
        else
          theStartDay = (DayOfWeek)(theStartDay - 1);
      }
    // fly home from the next airport
    return aTime + 
        fDestination->FlyHome(theStartDay, 
            theStartTime, theEndAirp);
  }
}

Airp **Airp::fAllAirports = 0;

long Airp::fNumAirports = 0;

Airp::Airp
Airp::Airp(Airport *theAirport)
{
  fFirstDep = 0;
  fTimeOffset = theAirport->timeOffset.hour * 60 +
          theAirport->timeOffset.min;
  fMinConnectTime = theAirport->minConnectTime.hour * 60 +
          theAirport->minConnectTime.min;
  fBeenHere = 0;
  fFirstArrival = 0x7fffffff;
  fPrevTime = 0;
}

Airp::~Airp
Airp::~Airp()
{
  Departure  *aDep;
  while (fFirstDep)
  {
    aDep = fFirstDep->fNextDep;
    delete fFirstDep;
    fFirstDep = aDep;
  }
}

Airp::AddFlight
void Airp::AddFlight(Departure *theDep)
{
  theDep->fNextDep = fFirstDep;
  fFirstDep = theDep;
}

Airp::ResetFirstArrivals
void Airp::ResetFirstArrivals()
{
  for (long aCount = 0; aCount < fNumAirports; aCount++)
  {
    fAllAirports[aCount]->fFirstArrival = 0x7fffffff;
    fAllAirports[aCount]->fPrevTime = 0;
  }
}

Airp::CalcExpectedTime
long Airp::CalcExpectedTime(DayOfWeek theStartDay,
  long theStartTime,
                        Airp *theEndAirp, long theCumTime,
                        long theFastestTime)
// theStartTime is GMT
{
  // calculate the expected time to get home from this airport
  Departure  *aFastestDep = 0;
  Departure  *aDep = fFirstDep;
  Departure  *aPrevDep = 0;
  long  aFastestTime = 0x7fffffff;
  long  aTime;
  
  if (fBeenHere) return -1;    // flying in circles
  if (theCumTime > fFirstArrival)  // there is a faster way to get here
    return -1;
  if (fPrevTime && (fPrevArrival == theStartTime) &&
    (fPrevDay == theStartDay))  // arrived here at the same time at another try
    return fPrevTime;  // the time to get home will be the same
  fPrevArrival = theStartTime;
  fPrevDay = theStartDay;
  fPrevTime = 0;
  // calculate time spent at this airport
  theStartTime = theStartTime + fMinConnectTime + fTimeOffset;
  if (theStartTime > kMinInADay)
  {
    theStartTime = theStartTime - kMinInADay;
    if (theStartDay == Saturday)
      theStartDay = Sunday;
    else
      theStartDay = (DayOfWeek)(theStartDay + 1);
  }
  else
    if (theStartTime < 0)
    {
      theStartTime = theStartTime + kMinInADay;
      if (theStartDay == Sunday)
        theStartDay = Saturday;
      else
        theStartDay = (DayOfWeek)(theStartDay - 1);
    }
  if (theCumTime + fMinConnectTime < theFastestTime)
  {
    fBeenHere = 1;
    // set the earliest arrival for every other airport
    // Peter can fly to from this airport
    while (aDep)
    {
      if (!aDep->fDestination->fBeenHere)
        aDep->SetFirstArrival(theStartDay, 
            theStartTime, theCumTime);
      aDep = aDep->fNextDep;
    }
    // try which flight might be the quickest way home
    aDep = fFirstDep;
    while (aDep)
    {
      if (!aDep->fDestination->fBeenHere)
      {
    aTime = aDep->CalcExpectedTime(theEndAirp, theFastestTime);
        if (aTime > 0)
        {
          if (aTime < aFastestTime)
          {
            aFastestTime = aTime;
            aFastestDep = aDep
          }
          aPrevDep = aDep;
          aDep = aDep->fNextDep;
        }
        else
          if (!aTime)  // didn't arrive home
          {
            // remove flight, it will never work
            if (aPrevDep)
            {
              aPrevDep->fNextDep = aDep->fNextDep;
              delete aDep;
              aDep = aPrevDep->fNextDep;
            }
            else
            {
              fFirstDep = aDep->fNextDep;
              delete aDep;
              aDep = fFirstDep;
            }
          }
          else
          {
            // too slow or going the wrong way
            aPrevDep = aDep;
            aDep = aDep->fNextDep;
          }
      }
      else
        aDep = aDep->fNextDep;
    }
    fBeenHere = 0;
    if (fFirstDep)
    {
      if (aFastestDep)
      {
        if (theCumTime + fMinConnectTime + aFastestTime < 
                                    theFastestTime)
        {
          fPrevTime = fMinConnectTime + aFastestTime;
          return fMinConnectTime + aFastestTime;
        }
        else
          return -1;  // slower
      }
      else
        return -1;  // didn't find a way home
    }
    else
      return 0;  // no fligths from here to theEndAirp
  }
  else
    return -1;  // slower
}

Airp::FlyHome
long Airp::FlyHome(DayOfWeek theStartDay, long theStartTime,
                    Airp *theEndAirp)
// theStartTime is GMT
{
  Departure  *aFastestDep = 0;
  Departure  *aDep = fFirstDep;
  Departure  *aPrevDep = 0;
  long  aFastestTime = 0x7fffffff;
  long  aTime;
  
  if (fBeenHere) return -1;  // flying in circles
  fBeenHere = 1;
  ResetFirstArrivals();  // delays may change earliest arrivals
  
  // calculate the time spent at this airport
  theStartTime += fMinConnectTime + fTimeOffset;
  if (theStartTime > kMinInADay)
  {
    theStartTime = theStartTime - kMinInADay;
    if (theStartDay == Saturday)
      theStartDay = Sunday;
    else
      theStartDay = (DayOfWeek)(theStartDay + 1);
  }
  else
    if (theStartTime < 0)
    {
      theStartTime = theStartTime + kMinInADay;
      if (theStartDay == Sunday)
        theStartDay = Saturday;
      else
        theStartDay = (DayOfWeek)(theStartDay - 1);
    }
  // set the earliest arrival for every other airport
  // Peter can fly to from this airport
  while (aDep)
  {
    if (!aDep->fDestination->fBeenHere)
      aDep->SetFirstArrival(theStartDay, theStartTime, 0);
    aDep = aDep->fNextDep;
  }
  // try which flight might be the quickest way home
  aDep = fFirstDep;
  while (aDep)
  {
    if (!aDep->fDestination->fBeenHere)  // don't fly in circles
    {
      aTime = aDep->CalcExpectedTime(theEndAirp, aFastestTime);
      if (aTime > 0)  // found a way home
      {
        if (aTime < aFastestTime)
        {
          // the fastest until now
          aFastestTime = aTime;
          aFastestDep = aDep;
        }
        aPrevDep = aDep;
        aDep = aDep->fNextDep;
      }
      else
        if (!aTime)  // didn't arrive home
        {
          if (aPrevDep)
          {
            aPrevDep->fNextDep = aDep->fNextDep;
            delete aDep;
            aDep = aPrevDep->fNextDep;
          }
          else
          {
            fFirstDep = aDep->fNextDep;
            delete aDep;
            aDep = fFirstDep;
          }
        }
        else
        {
          // too slow or going the wrong way
          aPrevDep = aDep;
          aDep = aDep->fNextDep;
        }
    }
    else
      aDep = aDep->fNextDep;
  }
  if (aFastestDep)
  return fMinConnectTime + aFastestDep->JumpOnAPlane(theStartDay,
                                theStartTime, theEndAirp);
  else
    return 0;
}

FindQuickestRoute
long FindQuickestRoute(      /* return travel time in seconds */
 AirportName departureAirport,  /* origin airport */
 AirportName arrivalAirport,    /* destination airport */
 DayOfWeek startDay,        /* day the adventure begins (local time) */
 MyTime startTime,          /* time the adventure begins (local time) */
 Airport airports[],        /* places to fly from/to */
 long numAirports,          /* number of entries in airports[] */
 Flight airlineSchedule[],  /* flights to choose from */
 long numFlights,          /* number of entries in airlineSchedule[] */
  GetFlightTime myGetFlightTime  /* callback that provides actual flight duration */
)
{
  Airp  **anAirPorts = new Airp*[numAirports];
  Airp  *aStartAirp = 0;  // where Peter starts
  Airp  *anEndAirp = 0;    // Peter's home
  Airp  *aDepAirp, *anArrAirp;
  Departure  *aDep;
  long  aAirpCount, aFlightCount, aTime;
  
  // make a forest of the airports and flights
  // each airport has a list of flights from that airport
  // each flight points to the next airport
  for (aAirpCount = 0; aAirpCount < numAirports; aAirpCount++)
  {
    anAirPorts[aAirpCount] = new Airp(&airports[aAirpCount]);
    if (!strcmp(airports[aAirpCount].name, departureAirport))
      aStartAirp = anAirPorts[aAirpCount];
    if (!strcmp(airports[aAirpCount].name, arrivalAirport))
      anEndAirp = anAirPorts[aAirpCount];
  }
  for (aFlightCount = 0; aFlightCount < 
              numFlights; aFlightCount++)
  {
    aDepAirp = 0;
    anArrAirp = 0;
    for (aAirpCount = 0; aAirpCount < numAirports; aAirpCount++)
    {
      if (!strcmp(airports[aAirpCount].name,
                airlineSchedule[aFlightCount].fromAirport))
      {
        aDepAirp = anAirPorts[aAirpCount];
        if (anArrAirp) break;
      }
      if (!strcmp(airports[aAirpCount].name,
                  airlineSchedule[aFlightCount].toAirport))
      {
        anArrAirp = anAirPorts[aAirpCount];
        if (aDepAirp) break;
      }
    }
    if (aDepAirp && anArrAirp && (aDepAirp != anArrAirp))
    {
      aDep = new Departure(&airlineSchedule[aFlightCount],
                        aDepAirp->fTimeOffset, anArrAirp);
      aDepAirp->AddFlight(aDep);
    }
  }
  Airp::fAllAirports = anAirPorts;
  Airp::fNumAirports = numAirports;
  Departure::fGetFlightTime = myGetFlightTime;
  aTime = aStartAirp->FlyHome(startDay,
      startTime.hour * 60 + startTime.min ñ 
            aStartAirp->fTimeOffset, anEndAirp);
  for (aAirpCount = 0; aAirpCount < numAirports; aAirpCount++)
    delete anAirPorts[aAirpCount];
  delete[] anAirPorts;
  return aTime * 60;
}
 

Community Search:
MacTech Search:

Software Updates via MacUpdate

SoftRAID 5.6.5 - High-quality RAID manag...
SoftRAID allows you to create and manage disk arrays to increase performance and reliability. SoftRAID allows the user to create and manage RAID 4 and 5 volumes, RAID 1+0, and RAID 1 (Mirror) and... Read more
Garmin Express 6.1.2.0 - Manage your Gar...
Garmin Express is your essential tool for managing your Garmin devices. Update maps, golf courses and device software. You can even register your device. Update maps Update software Register your... Read more
Airfoil 5.7.0 - Send audio from any app...
Airfoil allows you to send any audio to AirPort Express units, Apple TVs, and even other Macs and PCs, all in sync! It's your audio - everywhere. With Airfoil you can take audio from any... Read more
EtreCheck 4.0.4 - For troubleshooting yo...
EtreCheck is an app that displays the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to... Read more
WhatsApp 0.2.8361 - Desktop client for W...
WhatsApp is the desktop client for WhatsApp Messenger, a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS. WhatsApp Messenger is available for... Read more
iClock 4.2 - Customize your menubar cloc...
iClock is a menu-bar replacement for Apple's default clock but with 100x features. Have your Apple or Google calendar in the menubar. Have the day, date, and time in different fonts and colors in the... Read more
Things 3.4 - Elegant personal task manag...
Things is a task management solution that helps to organize your tasks in an elegant and intuitive way. Things combines powerful features with simplicity through the use of tags and its intelligent... Read more
Dashlane 5.7.0 - Password manager and se...
Dashlane is an award-winning service that revolutionizes the online experience by replacing the drudgery of everyday transactional processes with convenient, automated simplicity - in other words,... Read more
HoudahSpot 4.3.5 - Advanced file-search...
HoudahSpot is a versatile desktop search tool. Use HoudahSpot to locate hard-to-find files and keep frequently used files within reach. HoudahSpot will immediately feel familiar. It works just the... Read more
Parallels Desktop 13.3.0 - Run Windows a...
Parallels allows you to run Windows and Mac applications side by side. Choose your view to make Windows invisible while still using its applications, or keep the familiar Windows background and... Read more

Latest Forum Discussions

See All

Here's everything you need to know...
Alto's Odyssey is a really, really good game. If you don't believe me, you should definitely check out our review by clicking this link right here. It takes the ideas from the original Alto's Adventure, then subtly builds on them, creating... | Read more »
Alto's Odyssey (Games)
Alto's Odyssey 1.0.1 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.1 (iTunes) Description: Just beyond the horizon sits a majestic desert, vast and unexplored. Join Alto and his friends and set off on an endless... | Read more »
Vainglory 5v5: Everything you need to kn...
Vainglory just got bigger. [Read more] | Read more »
Check out these 5 games that are a lot l...
So you're in love with Minecraft, but you're looking for something else to play as well? You've come to the right place then, because this list is all about games that are a bit like Minecraft. Some of them, more than others. [Read more] | Read more »
Our top 5 characters from casual RPG Cre...
Creature Quest definitely lives up to its name with a host of collectible creatures based on fantasy tales and world mythologies. To celebrate Creature Quest’s first birthday, we’re going to lay out what we think are the five best characters in the... | Read more »
Around the Empire: What have you missed...
Did you know that Steel Media has a whole swathe of other sites dedicated to all aspects of mobile gaming? Sure you'll get the very best iPhone news, reviews, and opinions right here at 148Apps, but we don't want you missing out on a single piece... | Read more »
All the best games on sale for iPhone an...
Oh hi there, and welcome to our round-up of the best games that are currently on sale for iPhone and iPad. You thought I didn't see you there, did you, skulking behind the bushes? Trust me though, the bushes aren't where the best deals are. The... | Read more »
The Battle of Polytopia Guide - How to H...
A new update just released for The Battle of Polytopia (formerly Super Tribes), which introduces online multiplayer. For all the fans of Midjiwan’s lite take on Civilization, this is certainly welcome news, but playing online isn’t as easy and... | Read more »
Here are the very best mobile games to p...
It's Valentine's Day! Did you get loads of cards and chocolates and other tacky, simple expressions of human affection? Did you send out tat because you find it almost impossible to express emotion unless there's a section dedicated to it at your... | Read more »
Florence (Games)
Florence 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Florence is an interactive storybook from the award-winning lead designer of Monument Valley about the heart-racing highs and... | Read more »

Price Scanner via MacPrices.net

Lowest price of the year: 15″ 2.8GHz Apple Ma...
Amazon has the 2017 Space Gray 15″ 2.8GHz MacBook Pro on sale today for $251 off MSRP. Shipping is free: – 15″ 2.8GHz Touch Bar MacBook Pro Space Gray (MPTR2LL/A): $2148, $251 off MSRP Their price is... Read more
Apple restocks full line of Certified Refurbi...
Apple has restocked a full line of Apple Certified Refurbished 2017 13″ MacBook Pros for $200-$300 off MSRP. A standard Apple one-year warranty is included with each MacBook, and shipping is free.... Read more
Lowest sale price available for 13″ 1.8GHz Ma...
Focus Camera has the 2017 13″ 1.8GHz/128GB Apple MacBook Air on sale today for $829 including free shipping. Their price is $170 off MSRP, and it’s the lowest price available for a current 13″... Read more
21-inch 2.3GHz iMac on sale for $999, $100 of...
B&H Photo has the 2017 21″ 2.3GHz iMac (MMQA2LL/A) in stock and on sale for $999 including free shipping plus NY & NJ tax only. Their price is $100 off MSRP. Read more
Apple refurbished Mac minis in stock again st...
Apple has restocked Certified Refurbished Mac minis 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
Tuesday MacBook Deals: $250 off 15″ 2.9GHz Ma...
Adorama has the Silver 15″ 2.9GHz Apple MacBook Pro on sale today for $250 off MSRP. Shipping is free, and Adorama charges sales tax for residents in NY & NJ only: – 15″ 2.9GHz Silver MacBook Pro... Read more
Save up to $350 with these Apple Certified Re...
Apple has a full line of Certified Refurbished iMacs available for up to $350 off original MSRP. Apple’s one-year warranty is standard, and shipping is free. The following models are available: – 27... Read more
B&H offers $200 discount on Silver 15″ Ma...
B&H Photo has Silver 15″ Apple MacBook Pros on sale for $200 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 15″ 2.8GHz Touch Bar MacBook Pro Silver (... Read more
12″ Apple iPad Pro Sale of the Year! Models u...
B&H Photo has 12″ #iPad Pros on sale for up to $150 off MSRP. Shipping is free, and B&H charges sales tax in NY & NJ only: – 12″ 64GB WiFi iPad Pro: $719 $80 off MSRP – 12″ 256GB WiFi... Read more
Deals on 32GB 9″ iPads: Up to $50 off MSRP, s...
B&H Photo has 2017 9.7″ 32GB iPads on sale for $299 including free shipping plus NY & NJ sales tax only. Their price is $30 off MSRP, and it’s currently the lowest price available for these... Read more

Jobs Board

Sr. Experience Designer, Today at *Apple* -...
# Sr. Experience Designer, Today at Apple Job Number: 56495251 Santa Clara Valley, California, United States Posted: 18-Jan-2018 Weekly Hours: 40.00 **Job Summary** Read more
*Apple* Technical Specialist - Apple, Inc. (...
…customers purchase our products, you're the one who helps them get more out of their new Apple technology. Your day in the Apple Store is filled with a range of Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Strategist, *Apple* Media Products, Content...
# Strategist, Apple Media Products, Content and Marketing Job Number: 113399632 Santa Clara Valley, California, United States Posted: 20-Feb-2018 Weekly Hours: 40.00 Read more
*Apple* Store Leader - Retail District Manag...
Job Description:Job SummaryAs more and more people discover Apple , they visit our retail stores seeking ways to incorporate our products into their lives. It's your Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.