Largest Square Submatrix of all 1's NoSIMD_C#

Find the largest square submatrix consisting entirely of 1s as fast as possible.

Input

A 10,000 x 10,000 matrix of uint8 values (0 or 1) on STDIN.

0, 1, 0, 1, 1
0, 1, 1, 1, 1
0, 0, 1, 0, 0
1, 0, 1, 1, 0

Output

Print the side length of the largest all-ones square submatrix to STDOUT. The answer is guaranteed to be greater than 1.

For the example above, the output is:

2
Back to listJul 1, 2026 06:54Victor MerckléVictor MerckléError
Source Code

Source code access is restricted. Log in to request access.

Challenge History

No challenges yet.

Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jul 1, 2026 06:5609,103,9701,155,00002,117,632expected "54", got "50 "stderr
2Jul 1, 2026 06:561,8658,285,364746,00002,117,632stderr
3Jul 1, 2026 06:562,1508,298,106860,00002,117,632stderr
4Jul 1, 2026 06:562,3258,315,637930,00002,117,632stderr
5Jul 1, 2026 06:562,4428,473,986977,00002,117,632stderr
6Jul 1, 2026 06:562,5008,645,9321,000,00002,117,632stderr
7Jul 1, 2026 06:562,6828,602,5411,073,00002,117,632stderr
8Jul 1, 2026 06:562,7808,488,9241,112,00002,117,632stderr
9Jul 1, 2026 06:562,8058,533,2291,122,00002,117,632stderr