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 16, 2026 09:57Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 16, 2026 09:5809,158,1801,921,00002,113,536expected "52", got "50 "
2Jun 16, 2026 09:582,3408,523,173936,00002,113,536
3Jun 16, 2026 09:582,5209,971,8001,008,00002,113,536
4Jun 16, 2026 09:582,7778,796,9891,111,00002,113,536
5Jun 16, 2026 09:582,9128,414,8771,165,00002,113,536
6Jun 16, 2026 09:584,2709,160,4341,708,00002,113,536
7Jun 16, 2026 09:584,5929,709,2031,837,00002,113,536
8Jun 16, 2026 09:584,7559,334,7931,902,00002,113,536
9Jun 16, 2026 09:584,7659,362,8811,906,00002,113,536