TweetFollow Us on Twitter

Jul 95 Challenge
Volume Number:11
Issue Number:7
Column Tag:Programmer’s Challenge

Programmer’s Challenge

By Bob Boonstra and Mike Scanlin

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

Goodbye Mike

[Most of you are well aware of the excellence Mike Scanlin has brought to the magazine since the summer of 1992. Back then, Mike suggest to me that we start a programming puzzle to encourage programmers to write efficient code. Like many quality programmers, Mike was concerned that with the advent of faster machines, programmers were becoming lax in their ways.

The MacTech Programmer’s Challenge grew out of these conversations into the industry icon it is today. We’ve been stopped at trade shows and user group meetings by folks who are proudly wearing their MacTech Programmer’s Challenge Winner t-shirts. They should be proud - it is an accomplishment. We’re thrilled that the Challenge has had this impact on the developer community.

As publisher, working with Mike has been an absolute joy. After almost three years of running the challenge and devising puzzles, Mike is moving on. While his career has spanned such greats like WriteNow, PhotoFlash, and today General Magic, Mike cares about you all, the Challenge, and the magazine. So together, we’ve hand-picked someone we feel is the most qualified successor - Bob Boonstra.

Some of you might recognize Bob as a regular participant (and all-time winner) in past Challenges. Bob’s passion for efficiency dates back to his self-taught introduction to programming, starting in hex, then assembly language, and only later graduating to high level languages. He is a member of the Value-Added NewsWatcher team, adding a few features to John Norstad’s excellent newsreader. When he isn’t writing or reverse engineering code (or working at an unspecified day job), Bob spends time introducing his 8- and 10-year old children to the joys of hiking in the White Mountains, and to the world of Macintosh, but usually not both at the same time.

We wish Mike the best of luck and we welcome Bob with open arms. We hope you do as well. Ed./Pub. -nst]

Sprite Blitz

Most of you are probably familiar with the great shareware arcade games that are available for the Mac. This month you will be writing a key element of an arcade game - the code that moves graphic elements (“sprites”) across a background. There are a number of libraries that do much of this work for the aspiring game writer, but I want to see how fast you can do it, and hopefully we will all benefit from the techniques in the winning code.

The prototypes of the code you must write are as follows:

void StartGame(
/* pointer to CWindow */
 CWindowPtr theWind

short /*theSpriteID*/ AddSprite(
/* pointer to ‘cicn' */
 CIconPtr theSprite,
/* initial sprite location */
 Point startLoc 
); /* returns sprite ID to be used in MoveSprite, DeleteSprite */

void DeleteSprite(
/* ID of sprite to delete */
 short theSpriteID 

void MoveSprite(
/* ID of sprite to move */
 short theSpriteID,
/* amount to move sprite 
    NOTE: offset, not new location */
 Point amountToMove

void UpdateScreen(void);  

The problem works like this. Your routine StartGame will be called first and will be provided with a pointer to a color window. The window will be preset to a background that must be preserved, except for portions that are obscured by sprites. StartGame will not be timed, so you can do whatever initialization you need to do, like allocating an offscreen pixmap and initializing it to the contents of the window. Your routines AddSprite, DeleteSprite, and MoveSprite will then be called repeatedly to add, delete, and move sprites. Your routine UpdateScreen will also be called repeatedly, at which time you must redraw all sprites at their current locations and restore the background at their old locations.

Sprites will be provided to AddSprite as ‘cicn’ data structures, described in IM V-80 or NIM Imaging 4-105. Even though a ‘cicn’ can have an arbitrary shape, the sprites your code sees will have widths that are 1, 2, 4, 8, 16, or 32 pixels, to simplify things, but any height up to 32 pixels. A ‘cicn’ also has an associated mask, and you need to remember to show the correct part of the background through any holes in the mask. One way to draw the sprites, of course, is with the toolbox routine PlotCIcon, but you might find a better way

To simplify the problem, you can rely on (**theWind->portPixMap).bounds being longword aligned on a single monitor that is in 256 color mode, and on the pixelSize being 8 bits. The background will not change over time (i.e., you don’t have to handle a scrolling background). You can assume that there will be no more than 200 active sprites, and you can assume a sprite will not move more than 8 pixels horizontally or more than 8 pixels vertically in any given MoveSprite call. The color table of each sprite ‘cicn’ will be the same as that in the window PixMap. In a real game, you would probably do some collision detection on sprites, but our sprites will pass thru one another oblivious to the collision. In the event sprites overlap, you should draw them in the order that they were created by AddSprite (so that the sprite created last would be drawn over other sprites). You will need to do bounds checking of the sprite location against the window, because our sprites may move partially or completely out of the window.

This problem would be appropriate for an assembly language Challenge, but we’ll see how well you can do in straight C. Entries with obviously jerky visual effects will be considered less “correct” than those with smooth visual effects. I’ll select the winner from the correct entries based on how fast the code runs on a 68040 using the THINK C compiler, but - deadline permitting - I’ll also measure native execution time on a PowerPC. Now start blitting those sprites!

Two Months Ago Winner

Congratulations to Raffi Kasparian (Baltimore, MD) for having the fastest and smallest entry in the Hyphenation Challenge. Excellent job! This is Raffi’s second 1st place showing (he also won the Tile Windows Challenge in July 1993).

Here are the times and code sizes for the entries that worked. Numbers in parens after a person’s name indicate that person’s cumulative point total for all previous Programmer Challenges, not including this one:

Name time code

Raffi Kasparian (22) 99 348

Peter McA’Nulty 111 616

Ronald Nepsund (40) 121 402

Björn Davidsson 137 788

Robert Noll (20) 139 542

Bill Wade 165 462

Ernst Munter (60) 165 1036

Brian Moffat 171 1240

Dave Darrah (31) 220 666

Robert Westlund 293 476

Rick Genter 315 4276

D.H. 16928 978

E.O. 36536 764

M.D. 39727 3562

Raffi made the observation that there was a simpler rule that satisfied the given rules for hyphenating. This was not my intention (I try hard not to give trick Challenges) but I congratulate Raffi on finding this alternative. His main rule (given in his comments) is “Working forward from the beginning of the word until the last vowel is reached (not counting final e, es or ed), hyphenate every vowel-consonant pair unless the vowel is followed by a double consonant. In this case, hyphenate between the double consonant. This method meets the hyphenation requirements without having to deal directly with all the letter combination rules.” Needless to say, this simplifies the code quite a bit.

Many people wrote to me and asked about the “pairs of unsplitable pairs” rule. In the Challenge, I said, “No break is made between any two of the following letter combinations: sh, gh, p, ch, th, wh, gr, pr, cr, tr, wr, br, fr, dr, vowel-r, vowel-n, or om.” Then I proceeded to give a confusing example that wouldn’t have been hyphenated anyway because of other rules. Sorry. Here’s a better example: This hyphen in ‘chin-chilla’ is illegal because ‘in’ and ‘ch’ are both on the list of pairs that can’t have a hyphen between them. Some people misinterpreted the rule to mean “don’t hyphenate any of these pairs”. My apologies. Once again, I urge you to send e-mail to one of the Programmer Challenge addresses if there is any doubt about the stated rules.

As I said last month, I am turning this column over to Bob Boonstra. This month’s Sprite Blitz Challenge is Bob’s second puzzle. Next month is Bob’s first month at owning both halves of this column (a new puzzle and a previous answer). Please direct any future ideas, questions, or comments regarding this column to Bob at any of the Programmer Challenge addresses given in the front of the magazine.

So long and keep on optimizing!

Mike Scanlin

Top 20 Contestants of All Time

Here are the Top 20 Contestants for the 35 Programmer’s Challenges to date. The numbers below include points awarded for this months’ entrants. (Note: ties are listed alphabetically by last name - there are 24 people listed this month because 6 people have 20 points each.)

1. Boonstra, Bob 176

2. Karsh, Bill 71

3. Stenger, Allen 65

4. Larsson, Gustav 60

5. Munter, Ernst 60

6. Riha, Stepan 51

7. Goebel, James 49

8. Nepsund, Ronald 47

9. Cutts, Kevin 46

10. Mallett, Jeff 44

11. Kasparian, Raffi 42

12. Vineyard, Jeremy 40

13. Darrah, Dave 31

14. Landry, Larry 29

15. Elwertowski, Tom 24

16. Gregg, Xan 24

17. Lee, Johnny 22

18. Noll, Robert 22

19. Anderson, Troy 20

20. Burgoyne, Nick 20

21. Galway, Will 20

22. Israelson, Steve 20

23. Landweber, Greg 20

24. Pinkerton, Tom 20

There are three ways to earn points: (1) by scoring in the top 5 of any challenge, (2) by 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 5 points

suggesting challenge 2 points

Here is Raffi’s winning solution:

/*                     HY-PHEN-A-TION                               */
/*                                                             */
/*                   Raffi J. Kasparian                                 */
/*                                                             */
/* Please set the following three defines to appropriate    */
/* values if their default settings are not appropriate.              */

#define AllowMixedCaseDoubleConsonants                  true
/* if, for example, “Ss” or “sS” might occur in the       */
/* middle of the word (as in “paSsion”).                  */

#define AllowZeroLengthWords                           false
/* if the length byte might be a zero.                    */

#define AllowMultipleConsonants                         true
/* if multiple ( >2 ) same-consonants are po“sssss”ible.  */

#define uchar unsigned char
#define ulong unsigned long
#define kHyphen 0x2D
#define v( a ) ( a == 'A' || a == 'a' || \
                 a == 'E' || a == 'e' || \
                 a == 'I' || a == 'i' || \
                 a == 'O' || a == 'o' || \
                 a == 'U' || a == 'u' )

static Boolean vowelTable[128] = {
  v(0), v(1), v(2), v(3), v(4), v(5), v(6), v(7), v(8), 
  v(9), v(10), v(11), v(12), v(13), v(14), v(15), v(16), 
  v(17), v(18), v(19), v(20), v(21), v(22), v(23), v(24), 
  v(25), v(26), v(27), v(28), v(29), v(30), v(31), v(32), 
  v(33), v(34), v(35), v(36), v(37), v(38), v(39), v(40), 
  v(41), v(42), v(43), v(44), v(45), v(46), v(47), v(48), 
  v(49), v(50), v(51), v(52), v(53), v(54), v(55), v(56), 
  v(57), v(58), v(59), v(60), v(61), v(62), v(63), v(64), 
  v(65), v(66), v(67), v(68), v(69), v(70), v(71), v(72), 
  v(73), v(74), v(75), v(76), v(77), v(78), v(79), v(80), 
  v(81), v(82), v(83), v(84), v(85), v(86), v(87), v(88), 
  v(89), v(90), v(91), v(92), v(93), v(94), v(95), v(96), 
  v(97), v(98), v(99), v(100), v(101), v(102), v(103), 
  v(104), v(105), v(106), v(107), v(108), v(109), v(110), 
  v(111), v(112), v(113), v(114), v(115), v(116), v(117), 
  v(118), v(119), v(120), v(121), v(122), v(123), v(124), 
  v(125), v(126), v(127)

void *InitHyphenation( ulong maxRAM )
  return (void*)vowelTable;

void Hyphenate( privateDataPtr, inPtr, outPtr )
  void *privateDataPtr;
  Str255 *inPtr;
  Str255 *outPtr;
  #define mIsVowel( a ) ( ((Boolean*)privateDataPtr)[a] )
  #define mIsConsonant( a ) ( ! mIsVowel( a ) )

  #if AllowMixedCaseDoubleConsonants
    #define mIsDoubleConsonant( in )\
      ( *in == ( a = *( in + 1 ) ) || *in == a + 'a' - 'A' \
        || *in == a + 'A' - 'a' )
    #define mIsDoubleConsonant( in ) ( *in == *( in + 1 ) )
  register uchar *in, *out, *out0, *inLast, *lastVowel;
  #if AllowMixedCaseDoubleConsonants
    register uchar a;
  in = *inPtr;
  out = out0 = *outPtr;
  lastVowel = inLast = in + *in;

  /* working from back to front of the word, locate the   */
  /* last vowel not including final ‘e’, ‘es’, or ‘ed.    */
  if( mIsVowel( *lastVowel ) ){
    if( *lastVowel == 'e' || *lastVowel == 'E' ){
      goto FIND_LAST_VOWEL;
    else goto ALGORITHM;
  switch( *lastVowel-- ){
  case 's': case 'd': case 'S': case 'D':
    if( *lastVowel == 'e' || *lastVowel == 'E' )
  #if AllowZeroLengthWords
    case '\0': goto COPY_TO_END;
    if( lastVowel == in ) goto COPY_TO_END;
    if( mIsVowel( *lastVowel ) ) break;
  }while( true );

  /* Working forwards from the beginning of the word                */
  /* until lastVowel is reached, hyphenate every           */
  /* vowel/consonant pair unless the vowel is followed by                       */
  /* a double consonant.  In this case, hyphenate between                    */
  /* the double consonant.  This method meets the             */
  /* hyphenation requirements without having to deal               */
  /* directly with all the letter combination rules.            */
  *out++ = *in++; /* copy length byte */
  while( true ){
    while( mIsConsonant( *in ) )
      *out++ = *in++;                    
      if( in == lastVowel ) goto COPY_TO_END;
      *out++ = *in++;        
    }while( mIsVowel( *in ) );    
    /* handle double or multiple consonants               */
    #if AllowMultipleConsonants
      while( mIsDoubleConsonant( in ) ) *out++ = *in++;
      if( mIsDoubleConsonant( in ) ) *out++ = *in++;
    *out++ = kHyphen; *out++ = *in++; (*out0)++;
  COPY_TO_END: do *out++ = *in++; while( in <= inLast );
#undef mIsVowel
#undef mIsConsonant
#undef mIsDoubleConsonant


Community Search:
MacTech Search:

Software Updates via MacUpdate

Google Chrome 54.0.2840.71 - Modern and...
Google Chrome is a Web browser by Google, created to be a modern platform for Web pages and applications. It utilizes very fast loading of Web pages and has a V8 engine, which is a custom built... Read more
HoudahSpot 4.2.6 - Advanced file-search...
HoudahSpot is a powerful file 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 way... Read more
Yummy FTP Pro 1.11.11 - $29.99
Yummy FTP Pro is an advanced Mac file transfer app which provides a full-featured professional toolkit combined with blazing speeds and impeccable reliability, so whether you want to transfer a few... Read more
Shimo - VPN client – for everyon...
Shimo is the most versatile VPN client for OS X and it enables really everybody to master secure network. It supports more protocols than any other VPN application out there! CiscoVPN, AnyConnect,... Read more
Dash 3.4.0 - Instant search and offline...
Dash is an API documentation browser and code snippet manager. Dash helps you store snippets of code, as well as instantly search and browse documentation for almost any API you might use (for a full... Read more
AirRadar 3.1.9 - $9.95
With AirRadar, scanning for wireless networks is now easier and more personalized! It allows you to scan for open networks and tag them as favourites or filter them out. View detailed network... Read more
Printopia 2.1.22 - Share Mac printers wi...
Run Printopia on your Mac to share its printers to any capable iPhone, iPad or iPod Touch. Printopia will also add virtual printers, allowing you to save print-outs to your Mac and send to apps.... Read more
SteerMouse 5.0 - Powerful third-party mo...
SteerMouse is an advanced driver for USB and Bluetooth mice. It also supports Apple Mighty Mouse very well. SteerMouse can assign various functions to buttons that Apple's software does not allow,... Read more
Alarm Clock Pro 10.2.5 - $19.95
Alarm Clock Pro isn't just an ordinary alarm clock. Use it to wake you up in the morning, send and compose e-mails, remind you of appointments, randomize the iTunes selection, control an internet... Read more
Cocktail 10.1 - General maintenance and...
Cocktail is a general purpose utility for macOS that lets you clean, repair and optimize your Mac. It is a powerful digital toolset that helps hundreds of thousands of Mac users around the world get... Read more

Latest Forum Discussions

See All

Game of Dice is now available on Faceboo...
After celebrating its anniversary in style with a brand new update, there’s even more excitement in store for Game of Dice has after just being launched on Facebook Gameroom. A relatively new platform, Facebook Gameroom has been designed for PC... | Read more »
4 addictive clicker games like Best Fien...
Clickers are passive games that take advantage of basic human psychology to suck you in, and they're totally unashamed of that. As long as you're aware that this game has been created to take hold of your brain and leave you perfectly content to... | Read more »
Smile Inc. Guide: How not to die on the...
As if Mondays weren't bad enough, at Smile Inc. you have to deal with giant killer donuts, massive hungry staplers, and blasting zones. It's not exactly a happy, thriving work environment. In fact, you'll be lucky to survive the nine to five.... | Read more »
Oh...Sir! The Insult Simulator (Games)
Oh...Sir! The Insult Simulator 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: | Read more »
WitchSpring2 (Games)
WitchSpring2 1.27 Device: iOS Universal Category: Games Price: $3.99, Version: 1.27 (iTunes) Description: This is the story of Luna, the Moonlight Witch as she sets out into the world. This is a sequel to Witch Spring. Witch Spring 2... | Read more »
4 popular apps getting a Halloween makeo...
'Tis the season for all things spooky. So much, so, in fact, that even apps are getting into the spirt of things, dressing up in costume and spreading jack o' lanterns all about the place. These updates bring frightening new character skins, scary... | Read more »
Pokémon GO celebrates Halloween with can...
The folks behind Pokémon GO have some exciting things planned for their Halloween celebration, the first in-game event since it launched back in July. Starting October 26 and ending on November 1, trainers will be running into large numbers of... | Read more »
Best Fiends Forever Guide: How to collec...
The fiendship in Seriously's hit Best Fiends has been upgraded this time around in Best Fiends Forever. It’s a fast-paced clicker with lots of color and style--kind of reminiscent of a ‘90s animal mascot game like Crash Bandicoot. The game... | Read more »
5 apps for the budding mixologist
Creating your own cocktails is something of an art form, requiring a knack for unique tastes and devising interesting combinations. It's easy to get started right in your own kitchen, though, even if you're a complete beginner. Try using one of... | Read more »
5 mobile strategy games to try when you...
Strategy enthusiasts everywhere are celebrating the release of Civilization VI this week, and so far everyone seems pretty satisfied with the first full release in the series since 2010. The series has always been about ultra-addictive gameplay... | Read more »

Price Scanner via

Macs’ Superior Enterprise Deployment Cost Eco...
IBM’s debunking of conventional wisdom and popular mythology about the relative cost of using Apple Mac computers as opposed to PCs running Microsoft Windows at the sixth annual Jamf Nation User... Read more
12-inch WiFi Apple iPad Pros on sale for $50-...
B&H Photo has 12″ WiFi Apple iPad Pros on sale for $50-$70 off MSRP, each including free shipping. B&H charges sales tax in NY only: - 12″ Space Gray 32GB WiFi iPad Pro: $749 $50 off MSRP -... Read more
Apple refurbished 12-inch 128GB iPad Pros ava...
Apple has Certified Refurbished 12″ Apple iPad Pros available for up to $160 off the cost of new iPads. An Apple one-year warranty is included with each model, and shipping is free: - 32GB 12″ iPad... Read more
Apple refurbished iPad minis and iPad Air 2s...
Apple recently dropped prices on several Certified Refurbished iPad mini 4s and 2s as well as iPad Air 2s. An Apple one-year warranty is included with each model, and shipping is free: - 16GB iPad... Read more
MacHTTP-js Preview Full-featured Web Server f...
MacHTTP.Org has released MacHTTP-js Preview for macOS, a full-featured Web server for 21st Century desktops and servers. MacHTTP-js is a modern take on the classic stand-alone, desktop computer Web... Read more
Samsung Galaxy Tab A 10.1 with S Pen Makes US...
Samsung Electronics America, Inc. has announced the release of the Galaxy Tab A 10.1 with S Pen in a highly mobile, lightweight tablet. “With an embedded S Pen, consumers can discover more ways to... Read more
13-inch 2.5GHz MacBook Pro (Apple refurbished...
Apple has Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.5GHz MacBook Pros... 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
13-inch 2.5GHz MacBook Pro available for $927...
Overstock has the 13″ 2.5GHz MacBook Pro available for $926.99 including free shipping. Their price is $172 off MSRP. Read more
Apple refurbished 2015 13-inch MacBook Airs a...
Apple has Certified Refurbished 2015 13″ MacBook Airs available starting at $759. An Apple one-year warranty is included with each MacBook, and shipping is free: - 2015 13″ 1.6GHz/4GB/128GB MacBook... Read more

Jobs Board

Security Data Analyst - *Apple* Information...
…data sources need to be collected to allow Information Security to better protect Apple employees and customers from a wide range of threats.Act as the subject 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
*Apple* Solutions Consultant - Apple (United...
# Apple Solutions Consultant Job Number: 52812872 Houston, Texas, United States Posted: Oct. 18, 2016 Weekly Hours: 40.00 **Job Summary** As an Apple Solutions Read more
Lead *Apple* Solutions Consultant - Apple (...
# Lead Apple Solutions Consultant Job Number: 52812906 Houston, Texas, United States Posted: Oct. 18, 2016 Weekly Hours: 40.00 **Job Summary** The Lead ASC is an Read more
*Apple* Retail - Multiple Positions- Towson,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.