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 23:58Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 16, 2026 00:0008,473,7221,283,00002,113,536expected "51", got "50 "
2Jun 16, 2026 00:002,1357,937,675854,00002,113,536
3Jun 16, 2026 00:002,7808,348,7321,112,00002,113,536
4Jun 16, 2026 00:002,8228,280,7861,129,00002,113,536
5Jun 16, 2026 00:003,0208,366,5971,208,00002,113,536
6Jun 16, 2026 00:003,1128,377,4361,245,00002,113,536
7Jun 16, 2026 00:003,1578,407,9661,263,00002,113,536
8Jun 16, 2026 00:003,2508,438,7531,300,00002,113,536
9Jun 16, 2026 00:003,2779,586,1311,311,00002,113,536