Problem 658. Find the biggest empty box
You are given a matrix that contains only ones and zeros. Think of the ones as columns in an otherwise empty floor plan. You want to fit a big square into the empty space (denoted by zeros). What is the largest empty square sub-matrix you can find in the given matrix? You will return the row and column extent of the sub-matrix. The answer may not be unique. We will test that your sub-matrix is square, that it is empty, and that it contains the correct number of elements.
Example:
Input a = [ 1 0 0
0 0 0
0 0 0 ]
Output si = [ 2 3 2 3 ]
That is, the square indices are a(2:3,2:3). We verify that sum(sum(a(2:3,2:3))) is zero, and that it has four elements.
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David Hruska
on 9 Jun 2012
There appears to be an error is Test Suite #3.
Richard Zapor
on 10 Jun 2012
Agree, len for Test Suite 3 should be 4 not 3.
Ned Gulley
on 10 Jun 2012
Yes. Fixed it.
Jean-Marie Sainthillier
on 29 Nov 2012
Very exciting, as always with Ned
Brian Hannan
on 16 Jan 2015
Good puzzle!
Jerivington
on 10 Jun 2016
Challenging like all the other problems set in the ASEE Challenge
jmac
on 23 May 2020
Nice!
Dyuman Joshi
on 9 Jul 2022
Test suite has been updated with unsymmetrical matrices.
The original problem description/statement doesn't mention any restriction on the input matrix size.
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