Ponder This Challenge - May 2008 - Game of life - backwards

Ponder This Challenge:

This month's puzzle is about Conway's Game of life.
The game is a cellular automaton on a grid where in each generation, every cell determines its state (dead or alive) based on its eight neighbors: a dead cell will change its state to alive if and only if exactly three of its neighbors are alive; A live cell will stay alive if and only if two or three of its neighbors are alive.
All the changes are done simultaneously.
Find a possible state of the universe whose next generation is depicted below.

Click here to view the table

Aqua denote dead cells and blue denote alive cells.
Thanks to Dr. Yossi Elran for introducing the idea of Retro-Life.

We will post the names of those who submit a correct, original solution! If you don't want your name posted then please include such a statement in your submission!

We invite visitors to our website to submit an elegant solution. Send your submission to the ponder@il.ibm.com.

If you have any problems you think we might enjoy, please send them in. All replies should be sent to: ponder@il.ibm.com

Solution

• Click here to view the solution

  A possible solution is the following 33 live cells:

  We solved it using an algorithm for non-linear 0-1 (or pseudo-Boolean) optimization problems with integer coefficients. We used it separately for each letter and tweaked it a little to fit together.

  ---

  If you have any problems you think we might enjoy, please send them in. All replies should be sent to: ponder@il.ibm.com

Solvers

• Vladimir Sedach (05.02.2008 @05:50:39 PM EDT)
• Reinder Verlinde (05.02.2008 @07:16:41 PM EDT)
• Mark Perkins (05.05.2008 @11:36:45 AM EDT)
• Dennis Langdeau (05.05.2008 @04:56:22 PM EDT)
• Andreas Eisele (05.05.2008 @05:52:58 PM EDT)
• Balakrishnan V (05.05.2008 @07:02:20 PM EDT)
• Arthur Breitman (05.05.2008 @07:39:36 PM EDT)
• Frank Yang (05.05.2008 @10:42:20 PM EDT)
• Zhongyi Nie (05.06.2008 @01:44:12 AM EDT)
• Anthony P Jones (05.06.2008 @04:21:00 AM EDT)
• Gary M. Gerken (05.06.2008 @05:21:28 AM EDT)
• Jonas Martinsson (05.06.2008 @10:26:38 AM EDT)
• Michael Swart (05.06.2008 @11:07:35 AM EDT)
• Sanjeev Gupta (05.06.2008 @12:08:11 PM EDT)
• Mihai Cioc (05.06.2008 @12:56:36 PM EDT)
• Dan Dima (05.06.2008 @03:11:58 PM EDT)
• Daniel Bitin (05.06.2008 @05:47:09 PM EDT)
• Nyles Heise (05.07.2008 @12:47:35 AM EDT)
• Victor Chang (05.07.2008 @01:26:51 AM EDT)
• Fred Bone (05.07.2008 @06:26:03 AM EDT)
• Itzik L (05.07.2008 @06:36:22 AM EDT)
• Jochen Hoenicke (05.07.2008 @09:32:39 AM EDT)
• Phil Muhm (05.07.2008 @11:45:35 AM EDT)
• Albert Stadler (05.07.2008 @12:26:16 PM EDT)
• John T. Robinson (05.07.2008 @01:38:18 PM EDT)
• Novak Novakovic (05.07.2008 @02:17:52 PM EDT)
• Amos Guler (05.07.2008 @02:55:05 PM EDT)
• Gerald Fröhlich (05.07.2008 @04:59:00 PM EDT)
• Ernst Jaeger (05.07.2008 @05:41:18 PM EDT)
• Joe Barnett (05.07.2008 @06:14:52 PM EDT)
• Krunoslav Kovac (05.07.2008 @07:49:05 PM EDT)
• Arno Candel (05.07.2008 @09:03:03 PM EDT)
• Erin Malloy (+ Kyle Chapman) (05.08.2008 @12:58:54 AM EDT)
• Zhou Guang (05.08.2008 @05:04:45 AM EDT)
• Zvika Ben-Haim (05.08.2008 @08:58:56 AM EDT)
• Michael Schaaf (05.08.2008 @03:28:19 PM EDT)
• Alan O'Donnell (05.09.2008 @09:38:25 AM EDT)
• Alan Murray (05.09.2008 @11:30:29 AM EDT)
• Loukas Sidiropoulos (05.09.2008 @03:30:25 PM EDT)
• Chris Hills (05.09.2008 @06:45:52 PM EDT)
• Luke Pebody (05.09.2008 @07:02:04 PM EDT)
• Fabio Filatrella (05.10.2008 @02:17:55 PM EDT)
• Ganesh Lakshminarayana (05.11.2008 @02:17:55 PM EDT)
• Alexandru Sofronia (05.11.2008 @02:31:39 PM EDT)
• Shmuel Menachem Spiegel (05.11.2008 @09:47:31 PM EDT)
• Rob Pratt (05.11.2008 @10:03:04 PM EDT)
• Raj Mohan (05.12.2008 @07:09:20 PM EDT)
• Piotr Komisarski (05.12.2008 @07:16:21 PM EDT)
• John Douma (05.13.2008 @05:07:10 AM EDT)
• Clive Tong (05.13.2008 @10:00:50 AM EDT)
• Donald T Dodson (05.13.2008 @10:32:02 AM EDT)
• Roy Zywina (05.13.2008 @12:51:54 AM EDT)
• Ben Tarlow (05.14.2008 @11:20:43 AM EDT)
• Agnius Vasiliauskas (05.14.2008 @04:22:50 PM EDT)
• David Zimmermann (05.14.2008 @07:16:08 PM EDT)
• John G. Fletcher (05.14.2008 @08:32:59 PM EDT)
• Liubing Yu (05.15.2008 @01:07:57 AM EDT)
• Inga Maria Vosgerau (05.15.2008 @02:25:12 PM EDT)
• Aleksandar Damnjanovic (05.16.2008 @12:49:55 AM EDT)
• Dejan Stakic (05.16.2008 @09:52:17 AM EDT)
• Ashutosh Mahajan (05.16.2008 @11:00:43 AM EDT)
• Kort Eckman (05.16.2008 @07:08:32 PM EDT)
• Robert Szafranski (05.17.2008 @01:40:13 AM EDT)
• Alex Flora (05.17.2008 @08:17:28 PM EDT)
• Stephan Keil (05.18.2008 @05:45:35 AM EDT)
• Asaf Aharoni (05.18.2008 @04:25:00 PM EDT)
• Jesse Kolman (05.19.2008 @05:30:55 AM EDT)
• Travis Meyer (05.20.2008 @03:06:18 AM EDT)
• Máté Bartalos (05.21.2008 @09:25:29 AM EDT)
• David Johnson (05.22.2008 @02:30:06 PM EDT)
• Dave Englund (05.22.2008 @03:16:04 PM EDT)
• Sylvain Becker (05.22.2008 @06:53:30 PM EDT)
• Steffen Wolf (05.23.2008 @03:43:54 PM EDT)
• Fritz Schoenenberger (05.24.2008 @04:34:38 PM EDT)
• Urs Fässler (05.25.2008 @10:17:35 AM EDT)
• Ariel Kroszynski (05.26.2008 @02:58:49 AM EDT)
• Boris Nikolaus (05.28.2008 @10:36:07 AM EDT)
• Jiefeng Liang (05.28.2008 @04:14:20 AM EDT)
• Michael Wegener (05.29.2008 @12:53:15 PM EDT)
• Mindaugas Zaleckis (05.30.2008 @02:38:57 AM EDT)
• Adriano A. Batista (05.30.2008 @12:22:50 PM EDT)
• Ian Smith (05.31.2008 @12:27:37 AM EDT)
• Alok Jain (05.31.2008 @05:34:16 PM EDT)
• Mark Jones (06.01.2008 @03:44:21 AM EDT)
• Joseph C. Bonneau (06.01.2008 @01:32:17 PM EDT)