| Problem Name | Year | Location |
Problem A | Azulejos | 43rd 2019 | Porto, Portugal |
Problem B | Beautiful Bridges | 43rd 2019 | Porto, Portugal |
Problem C | Checks Post Facto | 43rd 2019 | Porto, Portugal |
Problem D | Circular DNA | 43rd 2019 | Porto, Portugal |
Problem E | Dead-End Detector | 43rd 2019 | Porto, Portugal |
Problem F | Directing Rainfall | 43rd 2019 | Porto, Portugal |
Problem G | First of Her Name | 43rd 2019 | Porto, Portugal |
Problem H | Hobson's Trains | 43rd 2019 | Porto, Portugal |
Problem I | Karel The Robot | 43rd 2019 | Porto, Portugal |
Problem J | Miniature Golf | 43rd 2019 | Porto, Portugal |
Problem K | Traffic Blights | 43rd 2019 | Porto, Portugal |
Problem A | Catch the Plane | 42nd 2018 | Beijing, China |
Problem B | Comma Sprinkler | 42nd 2018 | Beijing, China |
Problem C | Conquer the World | 42nd 2018 | Beijing, China |
Problem D | Gem Island | 42nd 2018 | Beijing, China |
Problem E | Getting a Jump on Crime | 42nd 2018 | Beijing, China |
Problem F | Go with the Flow | 42nd 2018 | Beijing, China |
Problem G | Panda Preserve | 42nd 2018 | Beijing, China |
Problem H | Single Cut of Failure | 42nd 2018 | Beijing, China |
Problem I | Triangles | 42nd 2018 | Beijing, China |
Problem J | Uncrossed Knight's Tour | 42nd 2018 | Beijing, China |
Problem K | Wireless is the New Fiber | 42nd 2018 | Beijing, China |
Problem A | Airport Construction | 41st 2017 | Rapid City, South Dakota |
Problem B | Get a Clue! | 41st 2017 | Rapid City, South Dakota |
Problem C | Mission Improbable | 41st 2017 | Rapid City, South Dakota |
Problem D | Money for Nothing | 41st 2017 | Rapid City, South Dakota |
Problem E | Need for Speed | 41st 2017 | Rapid City, South Dakota |
Problem F | Posterize | 41st 2017 | Rapid City, South Dakota |
Problem G | Replicate Replicate Rfplicbte | 41st 2017 | Rapid City, South Dakota |
Problem H | Scenery | 41st 2017 | Rapid City, South Dakota |
Problem I | Secret Chamber at Mount Rushmore | 41st 2017 | Rapid City, South Dakota |
Problem J | Son of Pipe Stream | 41st 2017 | Rapid City, South Dakota |
Problem K | Tarot Sham Boast | 41st 2017 | Rapid City, South Dakota |
Problem L | Visual Python++ | 41st 2017 | Rapid City, South Dakota |
Problem A | Balanced Diet | 40th 2016 | Phuket, Thailand |
Problem B | Branch Assignment | 40th 2016 | Phuket, Thailand |
Problem C | Ceiling Function | 40th 2016 | Phuket, Thailand |
Problem D | Clock Breaking | 40th 2016 | Phuket, Thailand |
Problem E | Forever Young | 40th 2016 | Phuket, Thailand |
Problem F | Longest Rivers | 40th 2016 | Phuket, Thailand |
Problem G | Oil | 40th 2016 | Phuket, Thailand |
Problem H | Polygon Puzzle | 40th 2016 | Phuket, Thailand |
Problem I | Road Times | 40th 2016 | Phuket, Thailand |
Problem J | Spin Doctor | 40th 2016 | Phuket, Thailand |
Problem K | String Theory | 40th 2016 | Phuket, Thailand |
Problem L | Swap Space | 40th 2016 | Phuket, Thailand |
Problem M | What Really Happened on Mars? | 40th 2016 | Phuket, Thailand |
Problem A | Amalgamated Artichokes | 39th 2015 | Marrakesh, Morocco |
Problem B | Asteroids | 39th 2015 | Marrakesh, Morocco |
Problem C | Catering | 39th 2015 | Marrakesh, Morocco |
Problem D | Cutting Cheese | 39th 2015 | Marrakesh, Morocco |
Problem E | Evolution in Parallel | 39th 2015 | Marrakesh, Morocco |
Problem F | Keyboarding | 39th 2015 | Marrakesh, Morocco |
Problem G | Pipe Stream | 39th 2015 | Marrakesh, Morocco |
Problem H | Qanat | 39th 2015 | Marrakesh, Morocco |
Problem I | Ship Traffic | 39th 2015 | Marrakesh, Morocco |
Problem J | Tile Cutting | 39th 2015 | Marrakesh, Morocco |
Problem K | Tours | 39th 2015 | Marrakesh, Morocco |
Problem L | Weather Report | 39th 2015 | Marrakesh, Morocco |
Problem M | Window Manager | 39th 2015 | Marrakesh, Morocco |
Problem A | Baggage | 38th 2014 | Ekaterinburg, Russia |
Problem B | Buffed Buffet | 38th 2014 | Ekaterinburg, Russia |
Problem C | Crane Balancing | 38th 2014 | Ekaterinburg, Russia |
Problem D | Game Strategy | 38th 2014 | Ekaterinburg, Russia |
Problem E | Maze Reduction | 38th 2014 | Ekaterinburg, Russia |
Problem F | Messenger | 38th 2014 | Ekaterinburg, Russia |
Problem G | Metal Processing Plant | 38th 2014 | Ekaterinburg, Russia |
Problem H | Pachinko | 38th 2014 | Ekaterinburg, Russia |
Problem I | Sensor Network | 38th 2014 | Ekaterinburg, Russia |
Problem J | Skiing | 38th 2014 | Ekaterinburg, Russia |
Problem K | Surveillance | 38th 2014 | Ekaterinburg, Russia |
Problem L | Wire Crossing | 38th 2014 | Ekaterinburg, Russia |
Problem A | Self-Assembly | 37th 2013 | St. Petersburg, Russia |
Problem B | Hey, Better Bettor | 37th 2013 | St. Petersburg, Russia |
Problem C | Surely You Congest | 37th 2013 | St. Petersburg, Russia |
Problem D | Factors | 37th 2013 | St. Petersburg, Russia |
Problem E | Harvard | 37th 2013 | St. Petersburg, Russia |
Problem F | Low Power | 37th 2013 | St. Petersburg, Russia |
Problem G | Map Tiles | 37th 2013 | St. Petersburg, Russia |
Problem H | Matрёшка | 37th 2013 | St. Petersburg, Russia |
Problem I | Pirate Chest | 37th 2013 | St. Petersburg, Russia |
Problem J | Pollution Solution | 37th 2013 | St. Petersburg, Russia |
Problem K | Up a Tree | 37th 2013 | St. Petersburg, Russia |
Problem A | Asteroid Rangers | 36th 2012 | Warsaw, Poland |
Problem B | Curvy Little Bottles | 36th 2012 | Warsaw, Poland |
Problem C | Bus Tour | 36th 2012 | Warsaw, Poland |
Problem D | Fibonacci Words | 36th 2012 | Warsaw, Poland |
Problem E | Infiltration | 36th 2012 | Warsaw, Poland |
Problem F | Keys | 36th 2012 | Warsaw, Poland |
Problem G | Minimum Cost Flow | 36th 2012 | Warsaw, Poland |
Problem H | Room Service | 36th 2012 | Warsaw, Poland |
Problem I | A Safe Bet | 36th 2012 | Warsaw, Poland |
Problem J | Shortest Flight Path | 36th 2012 | Warsaw, Poland |
Problem K | Stacking Plates | 36th 2012 | Warsaw, Poland |
Problem L | Takeover Wars | 36th 2012 | Warsaw, Poland |
Problem A | To Add or to Multiply | 35th 2011 | Orlando, Florida |
Problem B | Affine Mess | 35th 2011 | Orlando, Florida |
Problem C | Ancient Messages | 35th 2011 | Orlando, Florida |
Problem D | Chips Challenge | 35th 2011 | Orlando, Florida |
Problem E | Coffee Central | 35th 2011 | Orlando, Florida |
Problem F | Machine Works | 35th 2011 | Orlando, Florida |
Problem G | Magic Sticks | 35th 2011 | Orlando, Florida |
Problem H | Mining Your Own Busniss | 35th 2011 | Orlando, Florida |
Problem I | Mummy Madness | 35th 2011 | Orlando, Florida |
Problem J | Pyramids | 35th 2011 | Orlando, Florida |
Problem K | Trash Removal | 35th 2011 | Orlando, Florida |
Problem A | APL Lives! | 34th 2010 | Harbin, China |
Problem B | Barcodes | 34th 2010 | Harbin, China |
Problem C | Tracking Bio-bots | 34th 2010 | Harbin, China |
Problem D | Castles | 34th 2010 | Harbin, China |
Problem E | Channel | 34th 2010 | Harbin, China |
Problem F | Contour Mapping | 34th 2010 | Harbin, China |
Problem G | Islands, The | 34th 2010 | Harbin, China |
Problem H | Rain | 34th 2010 | Harbin, China |
Problem I | Robots on Ice | 34th 2010 | Harbin, China |
Problem J | Sharing Chocolate | 34th 2010 | Harbin, China |
Problem K | Paperweight | 34th 2010 | Harbin, China |
Problem A | Careful Approach, A | 33rd 2009 | Stockholm, Sweden |
Problem B | My Bad | 33rd 2009 | Stockholm, Sweden |
Problem C | Return of Carl, The | 33rd 2009 | Stockholm, Sweden |
Problem D | Conduit Packing | 33rd 2009 | Stockholm, Sweden |
Problem E | Fare and Balanced | 33rd 2009 | Stockholm, Sweden |
Problem F | Deer-Proof Fence | 33rd 2009 | Stockholm, Sweden |
Problem G | House of Cards | 33rd 2009 | Stockholm, Sweden |
Problem H | Ministers' Major Mess, The | 33rd 2009 | Stockholm, Sweden |
Problem I | Struts and Springs | 33rd 2009 | Stockholm, Sweden |
Problem J | Subway Timing | 33rd 2009 | Stockholm, Sweden |
Problem K | Suffix-Replacement Grammars | 33rd 2009 | Stockholm, Sweden |
Problem A | Air Conditioning Machinery | 32nd 2008 | Banff, Canada |
Problem B | Always an Integer | 32nd 2008 | Banff, Canada |
Problem C | Conveyor Belt | 32nd 2008 | Banff, Canada |
Problem D | Hare and the Hounds, The | 32nd 2008 | Banff, Canada |
Problem E | Huffman Codes | 32nd 2008 | Banff, Canada |
Problem F | Glenbow Museum | 32nd 2008 | Banff, Canada |
Problem G | Net Loss | 32nd 2008 | Banff, Canada |
Problem H | Painter | 32nd 2008 | Banff, Canada |
Problem I | Password Suspects | 32nd 2008 | Banff, Canada |
Problem J | Sky is the Limit, The | 32nd 2008 | Banff, Canada |
Problem A | Consanguine Calculations | 31st 2007 | Tokyo, Japan |
Problem B | Containers | 31st 2007 | Tokyo, Japan |
Problem C | Grand Prix | 31st 2007 | Tokyo, Japan |
Problem D | Jacquard Circuits | 31st 2007 | Tokyo, Japan |
Problem E | Collecting Luggage | 31st 2007 | Tokyo, Japan |
Problem F | Marble Game | 31st 2007 | Tokyo, Japan |
Problem G | Network | 31st 2007 | Tokyo, Japan |
Problem H | Raising the Roof | 31st 2007 | Tokyo, Japan |
Problem I | Water Tanks | 31st 2007 | Tokyo, Japan |
Problem J | Tunnels | 31st 2007 | Tokyo, Japan |
Problem A | Low Cost Air Travel | 30th 2006 | San Antonio, Texas |
Problem B | Remember the A La Mode! | 30th 2006 | San Antonio, Texas |
Problem C | Ars Longa | 30th 2006 | San Antonio, Texas |
Problem D | Bipartite Numbers | 30th 2006 | San Antonio, Texas |
Problem E | Bit Compressor | 30th 2006 | San Antonio, Texas |
Problem F | Building a Clock | 30th 2006 | San Antonio, Texas |
Problem G | Pilgrimage | 30th 2006 | San Antonio, Texas |
Problem H | Pockets | 30th 2006 | San Antonio, Texas |
Problem I | Degrees of Separation | 30th 2006 | San Antonio, Texas |
Problem J | Routing | 30th 2006 | San Antonio, Texas |
Problem A | Eyeball Benders | 29th 2005 | Shanghai, China |
Problem B | Simplified GSM Network | 29th 2005 | Shanghai, China |
Problem C | Traveling Judges Problem, The | 29th 2005 | Shanghai, China |
Problem D | cNteShruPfefrlefe [Near Perfect Shuffle] | 29th 2005 | Shanghai, China |
Problem E | Lots of Sunlight | 29th 2005 | Shanghai, China |
Problem F | Crossing Streets | 29th 2005 | Shanghai, China |
Problem G | Tiling the Plane | 29th 2005 | Shanghai, China |
Problem H | Great Wall Game, The | 29th 2005 | Shanghai, China |
Problem I | Workshops | 29th 2005 | Shanghai, China |
Problem J | Zones | 29th 2005 | Shanghai, China |
Problem A | Carl the Ant | 28th 2004 | Prague, Czech Republic |
Problem B | Heliport | 28th 2004 | Prague, Czech Republic |
Problem C | Image Is Everything | 28th 2004 | Prague, Czech Republic |
Problem D | Insecure In Prague | 28th 2004 | Prague, Czech Republic |
Problem E | Intersecting Dates | 28th 2004 | Prague, Czech Republic |
Problem F | Merging Maps | 28th 2004 | Prague, Czech Republic |
Problem G | Navigation | 28th 2004 | Prague, Czech Republic |
Problem H | Tree-Lined Streets | 28th 2004 | Prague, Czech Republic |
Problem I | Suspense | 28th 2004 | Prague, Czech Republic |
Problem J | Air Traffic Control | 28th 2004 | Prague, Czech Republic |
Problem A | Building Bridges | 27th 2003 | Beverly Hills, California |
Problem B | Light Bulbs | 27th 2003 | Beverly Hills, California |
Problem C | Riding the Bus | 27th 2003 | Beverly Hills, California |
Problem D | Eurodiffusion | 27th 2003 | Beverly Hills, California |
Problem E | Covering Whole Holes | 27th 2003 | Beverly Hills, California |
Problem F | Combining Images | 27th 2003 | Beverly Hills, California |
Problem G | Linking Loader, A | 27th 2003 | Beverly Hills, California |
Problem H | Spy in the Metro, A | 27th 2003 | Beverly Hills, California |
Problem I | Solar System, The | 27th 2003 | Beverly Hills, California |
Problem A | Balloons in a Box | 26th 2002 | Honolulu, Hawaii |
Problem B | Undecodable Codes | 26th 2002 | Honolulu, Hawaii |
Problem C | Crossing the Desert | 26th 2002 | Honolulu, Hawaii |
Problem D | Ferries | 26th 2002 | Honolulu, Hawaii |
Problem E | Island Hopping | 26th 2002 | Honolulu, Hawaii |
Problem F | Toil for Oil | 26th 2002 | Honolulu, Hawaii |
Problem G | Partitions | 26th 2002 | Honolulu, Hawaii |
Problem H | Silly Sort | 26th 2002 | Honolulu, Hawaii |
Problem I | Merrily, We Roll Along! | 26th 2002 | Honolulu, Hawaii |
Problem A | Airport Configuration | 25th 2001 | Vancouver, Canada |
Problem B | Say Cheese | 25th 2001 | Vancouver, Canada |
Problem C | Crossword Puzzle | 25th 2001 | Vancouver, Canada |
Problem D | Can't Cut Down the Forest for the Trees | 25th 2001 | Vancouver, Canada |
Problem E | Geoduck GUI, The | 25th 2001 | Vancouver, Canada |
Problem F | Major Problem, A | 25th 2001 | Vancouver, Canada |
Problem G | Fixed Partition Memory Management | 25th 2001 | Vancouver, Canada |
Problem H | Professor Monotonic's Networks | 25th 2001 | Vancouver, Canada |
Problem A | Abbott's Revenge | 24th 2000 | Orlando, Florida |
Problem B | According to Bartjens | 24th 2000 | Orlando, Florida |
Problem C | Cutting Chains | 24th 2000 | Orlando, Florida |
Problem D | Gifts Large and Small | 24th 2000 | Orlando, Florida |
Problem E | Internet Bandwidth | 24th 2000 | Orlando, Florida |
Problem F | Page Hoping | 24th 2000 | Orlando, Florida |
Problem G | Queue and A | 24th 2000 | Orlando, Florida |
Problem H | Stopper Stumper | 24th 2000 | Orlando, Florida |
Problem A | Bee Breeding | 23nd 1999 | Eindhoven, The Netherlands |
Problem B | Bullet Hole | 23nd 1999 | Eindhoven, The Netherlands |
Problem C | Dicey Problem, A | 23nd 1999 | Eindhoven, The Netherlands |
Problem D | Fortified Forest, The | 23nd 1999 | Eindhoven, The Netherlands |
Problem E | Trade on Verweggistan | 23nd 1999 | Eindhoven, The Netherlands |
Problem F | Robot | 23nd 1999 | Eindhoven, The Netherlands |
Problem G | Letter Carrier's Rounds, The | 23nd 1999 | Eindhoven, The Netherlands |
Problem H | Flooded! | 23nd 1999 | Eindhoven, The Netherlands |
Problem A | Crystal Clear | 22nd 1998 | Atlanta, Georgia |
Problem B | Flight Planning | 22nd 1998 | Atlanta, Georgia |
Problem C | Lead or Gold | 22nd 1998 | Atlanta, Georgia |
Problem D | Page Selection by Keyword Matching | 22nd 1998 | Atlanta, Georgia |
Problem E | Petri Net Simulation | 22nd 1998 | Atlanta, Georgia |
Problem F | Polygon Intersections | 22nd 1998 | Atlanta, Georgia |
Problem G | Spatial Structures | 22nd 1998 | Atlanta, Georgia |
Problem H | Towers of Powers | 22nd 1998 | Atlanta, Georgia |
Problem A | System Dependencies | 21st 1997 | San Jose, California |
Problem B | Jill Rides Again | 21st 1997 | San Jose, California |
Problem C | Morse Mismatches | 21st 1997 | San Jose, California |
Problem D | Raid! | 21st 1997 | San Jose, California |
Problem E | Optimal Routing | 21st 1997 | San Jose, California |
Problem F | Do you know the way to San Jose | 21st 1997 | San Jose, California |
Problem G | Spreadsheet Tracking | 21st 1997 | San Jose, California |
Problem H | Window Frames | 21st 1997 | San Jose, California |
Problem A | 10-20-30 | 20th 1996 | Philadelphia, Pennsylvania |
Problem B | Calling Circles | 20th 1996 | Philadelphia, Pennsylvania |
Problem C | Cutting Corners | 20th 1996 | Philadelphia, Pennsylvania |
Problem D | Bang the Drum Slowly | 20th 1996 | Philadelphia, Pennsylvania |
Problem E | Pattern Matching Prelims | 20th 1996 | Philadelphia, Pennsylvania |
Problem F | Nondeterministic Trellis Automata | 20th 1996 | Philadelphia, Pennsylvania |
Problem G | Trucking | 20th 1996 | Philadelphia, Pennsylvania |
Problem A | Jill's Bike | 19th 1995 | Nashville, Tennessee |
Problem B | Tempus et mobilius (Time and Motion) | 19th 1995 | Nashville, Tennessee |
Problem C | Variable Radix Huffman Encoding | 19th 1995 | Nashville, Tennessee |
Problem D | Sail Race | 19th 1995 | Nashville, Tennessee |
Problem E | Stamps | 19th 1995 | Nashville, Tennessee |
Problem F | Theseus and the Minotaur | 19th 1995 | Nashville, Tennessee |
Problem G | Train Time | 19th 1995 | Nashville, Tennessee |
Problem H | Uncompress | 19th 1995 | Nashville, Tennessee |
Problem A | Borrowers | 18th 1994 | Phoenix, Arizona |
Problem B | Testing the CATCHER | 18th 1994 | Phoenix, Arizona |
Problem C | Crossword Answers | 18th 1994 | Phoenix, Arizona |
Problem D | Package Pricing | 18th 1994 | Phoenix, Arizona |
Problem E | Switching Channels | 18th 1994 | Phoenix, Arizona |
Problem F | Typesetting | 18th 1994 | Phoenix, Arizona |
Problem G | Vessel Traffic Advisory Service | 18th 1994 | Phoenix, Arizona |
Problem H | Monitoring Wheelchair Patients | 18th 1994 | Phoenix, Arizona |
Problem A | Budget Travel | 17th 1993 | Indianapolis, Indiana |
Problem B | Classifying Lots in a Subdivision | 17th 1993 | Indianapolis, Indiana |
Problem C | Kissin' Cousins | 17th 1993 | Indianapolis, Indiana |
Problem D | Golygons | 17th 1993 | Indianapolis, Indiana |
Problem E | MIDI Preprocessing | 17th 1993 | Indianapolis, Indiana |
Problem F | Puzzle | 17th 1993 | Indianapolis, Indiana |
Problem G | Resource Allocation | 17th 1993 | Indianapolis, Indiana |
Problem H | Scanner | 17th 1993 | Indianapolis, Indiana |
Problem A | Spreadsheet Calculator | 16th 1992 | Kansas City, Missouri |
Problem B | Getting in Line | 16th 1992 | Kansas City, Missouri |
Problem C | Radio Direction Finder | 16th 1992 | Kansas City, Missouri |
Problem D | Moth Eradication | 16th 1992 | Kansas City, Missouri |
Problem E | Department of Redundancy Department | 16th 1992 | Kansas City, Missouri |
Problem F | Othello | 16th 1992 | Kansas City, Missouri |
Problem G | Urban Elevations | 16th 1992 | Kansas City, Missouri |
Problem A | Firetruck | 15th 1991 | San Antonio, Texas |
Problem B | Triangular Vertices | 15th 1991 | San Antonio, Texas |
Problem C | Concurrency Simulator | 15th 1991 | San Antonio, Texas |
Problem D | Domino Effect, The | 15th 1991 | San Antonio, Texas |
Problem E | Use of Hospital Facilities | 15th 1991 | San Antonio, Texas |
Problem F | Message Decoding | 15th 1991 | San Antonio, Texas |
Problem G | Code Generation | 15th 1991 | San Antonio, Texas |