This problem is related to the 17x17 challenge. See also Part 1 of this problem. Given a matrix in which each element is either 1, 2, 3, or 4, determine whether or not any rectangles are present. A rectangle is a formed whenever four instances of the same value appear in the corners of a rectangular region of the matrix.
Examples:
Input a = [ 4 1 2 4 1
3 3 2 1 4
3 2 4 1 1
1 4 3 2 2
1 1 1 4 4 ]
Output tf is false
You can't form any rectangles here.
Input a = [ 1 4 3 1
3 1 4 1
1 3 4 1
1 1 2 3 ]
Output tf is true
There is a rectangle: a([1 3],[1 4]) is [1 1; 1 1]
Solve

Solution Stats

290 Solutions

144 Solvers

Last Solution submitted on Aug 14, 2026

Last 200 Solutions

Problem Comments

Solution Comments

Show comments

Problem Recent Solvers144

wsf Cameron Maslan Feras Alhazzaa Hunger

Suggested Problems

More from this Author54

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!