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 listJun 15, 2026 07:50Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 15, 2026 07:5208,422,1141,435,00002,113,536expected "52", got "50 "
2Jun 15, 2026 07:522,4158,121,411966,00002,113,536
3Jun 15, 2026 07:522,6608,208,4701,064,00002,113,536
4Jun 15, 2026 07:523,0378,344,7561,215,00002,113,536
5Jun 15, 2026 07:523,4358,577,0501,374,00002,113,536
6Jun 15, 2026 07:523,6128,629,2551,445,00002,113,536
7Jun 15, 2026 07:523,6158,678,7801,446,00002,113,536
8Jun 15, 2026 07:523,7008,632,4751,480,00002,113,536
9Jun 15, 2026 07:524,0208,828,7291,608,00002,113,536