Problem 52. What is the next step in Conway's Life?

Created by Cody Team

Solve Later

Given a matrix A that represents the state of Conway's game of Life at one instant (time t=n), return the matrix B that represents the state of the game at the next instant (time t=n+1).

Assume a toroidal game board, so the edges of the matrix wrap left to right and top to bottom.

Examples:

 Input  A = [ 1   1   0   0
              0   1   0   0
              1   1   0   0
              0   0   0   0 ]

 Output B = [ 1   1   0   0
              0   0   1   0
              1   1   0   0
              0   0   0   0 ]

 Input  A = [ 0   1   1   0
              1   1   1   0
              0   0   1   0
              0   0   0   0 ]

 Output B = [ 1   0   1   1
              1   0   0   0
              0   0   1   1
              0   1   1   0 ]

Solve

Solution Stats

1459 Solutions
442 Solvers

Last Solution submitted on Feb 21, 2020

Last 200 Solutions

Problem Comments

5 Comments

5 Comments

Show 2 older comments

David Young on 5 Feb 2012

I think test sets should be designed to encourage general solutions. At present, the test set only has square boards - some more varied examples would make solvers seek code that is general.

mItk on 17 Oct 2016

Is there something wrong with the test suite? function B = life(A) B = A; end produces "Error using life Too many output arguments." See comment on solution 1019804.

mItk on 17 Oct 2016

I suppose the error "Error using life Too many output arguments." is due to shadowing. It seems thet test suite calls \toolbox\matlab\demos\life.m

shahriar memaran on 9 Mar 2017

I had so much fun with this problem. Thank you.

David Verrelli on 7 Feb 2018

Is there a syntax flaw in the Test Suite? Currently the first test displays with a first line of "%%A = [ ...", and in my solution (S 1435695) only the second test is displayed. Although apparently the first test is still being called (S 1435709)?

Solution Comments

Solution 1019804

1 Comment

1 Comment

mItk on 17 Oct 2016

Is there something wrong with the test suite?

function B = life(A)
B = A;
end

produces "Error using life Too many output arguments."

Solution 598431

1 Comment

1 Comment

Alison on 18 Mar 2015

This solution is for only a 4x4 A. See Solution 598430 for general solution.

Solution 598430

1 Comment

1 Comment

Alison on 18 Mar 2015

This is the solution for A of any size.

Solution 144659

1 Comment

1 Comment

Nicholas Howe on 5 Oct 2012

Ties the current leader in size, but works on all board sizes.

Solution 61610

1 Comment

1 Comment

Cris Luengo on 14 Jul 2012

This stops working if the input is not 4x4.

Solution 30146

1 Comment

1 Comment

Peter Wittenberg on 2 Apr 2012

Nice way of expanding A for circular convolution

Solution 29999

1 Comment

1 Comment

David Young on 5 Feb 2012

Humph! Solution 2234 uses imfilter, but this fails with imfilter not found!

Solution 29957

1 Comment

1 Comment

David Young on 5 Feb 2012

Nice - but only works for 4x4 boards.

Solution 29512

1 Comment

1 Comment

David Young on 5 Feb 2012

Puzzling - solution 2231 uses imfilter but this solution fails because padarray isn't available. Both are in the IPT.

Solution 14719

2 Comments

2 Comments

Peter Wittenberg on 2 Apr 2012

Nice usage of a simpler matrix for convolution (ones(3)) and readjustment of the logical conditions.

lkjslkjdlk on 23 Sep 2013

Good job!

Solution 2231

3 Comments

3 Comments

Peter Wittenberg on 2 Apr 2012

I was looking for a command to do a circular convolution, but couldn't figure it out. This is useful to learn and, I guess, the whole point of Cody

Martijn on 6 Jun 2015

However, learning is severely hindered by not being able to view solutions of smaller size. At least, as far as i know, this is not possible.

David Verrelli on 7 Feb 2018

_All_ solutions in this Problem will become viewable after you solve _another_ Problem in the same category (which here is "Cody Challenge").

Problem Recent Solvers442

Problem Tags

automata life

Problem 52. What is the next step in Conway's Life?

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers442

Suggested Problems

More from this Author95

Problem Tags

Problem 52. What is the next step in Conway's Life?

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers442

Suggested Problems

More from this Author95

Problem Tags

Players