Problem 512. Spot the rectangle
This problem is related to the 17x17 challenge. Given a matrix filled with ones and zeros, determine whether or not any rectangles are present. A rectangle is a formed whenever four ones appear in the corners of a rectangular region of the matrix.
Examples:
Input a = [ 1 0 0 0 0
0 0 0 1 0
0 0 0 0 1
0 0 0 0 1
0 0 1 0 0 ]
Output tf is false
You can't form any rectangles here.
Input a = [ 1 0 1 0
0 0 1 0
1 0 1 0
0 0 1 1 ]
Output tf is true
There is a rectangle: a([1 3],[1 3]) is [1 1; 1 1]
Solution Stats
Problem Comments
-
3 Comments
rifat
on 15 Jun 2014
test cases imply that the question title should be "spot the square"
Ned Gulley
on 14 Jan 2015
I added a rectangular (non-square) test case. Thanks for the note.
Christian Schröder
on 28 Sep 2022
Could you add
a = ones(3) - eye(3)
to the test suite?
Solution Comments
Show commentsProblem Recent Solvers110
Suggested Problems
-
12738 Solvers
-
Project Euler: Problem 2, Sum of even Fibonacci
2000 Solvers
-
Square Digits Number Chain Terminal Value (Inspired by Project Euler Problem 92)
212 Solvers
-
550 Solvers
-
Return fibonacci sequence do not use loop and condition
479 Solvers
More from this Author50
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!