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 18:55Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 15, 2026 18:5608,931,4071,228,00002,113,536expected "53", got "50 "
2Jun 15, 2026 18:562,1178,564,904847,00002,113,536
3Jun 15, 2026 18:562,4428,340,519977,00002,113,536
4Jun 15, 2026 18:562,6158,771,0951,046,00002,113,536
5Jun 15, 2026 18:562,6678,509,7781,067,00002,113,536
6Jun 15, 2026 18:562,7658,516,8711,106,00002,113,536
7Jun 15, 2026 18:562,8478,403,2391,139,00002,113,536
8Jun 15, 2026 18:562,8508,523,8141,140,00002,113,536
9Jun 15, 2026 18:563,06710,497,0121,227,00002,113,536