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 17, 2026 07:33Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 17, 2026 07:3408,507,5141,279,00002,113,536expected "53", got "50 "
2Jun 17, 2026 07:341,8528,200,377741,00002,113,536
3Jun 17, 2026 07:341,9208,121,262768,00002,113,536
4Jun 17, 2026 07:342,2528,358,965901,00002,113,536
5Jun 17, 2026 07:342,7408,508,1871,096,00002,113,536
6Jun 17, 2026 07:343,1358,498,1741,254,00002,113,536
7Jun 17, 2026 07:343,2478,897,4381,299,00002,113,536
8Jun 17, 2026 07:343,3178,571,2741,327,00002,113,536
9Jun 17, 2026 07:343,41510,148,1631,366,00002,113,536