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 8, 2026 20:38Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 8, 2026 20:3909,910,1011,017,00002,113,536expected "60", got "50 "
2Jun 8, 2026 20:3908,535,299972,00002,113,536expected "54", got "50 "
3Jun 8, 2026 20:391,9678,240,156787,00002,113,536
4Jun 8, 2026 20:392,1958,326,848878,00002,113,536
5Jun 8, 2026 20:392,2208,327,755888,00002,113,536
6Jun 8, 2026 20:392,3008,366,540920,00002,113,536
7Jun 8, 2026 20:392,4928,485,688997,00002,113,536
8Jun 8, 2026 20:392,5378,482,2211,015,00002,113,536
9Jun 8, 2026 20:392,7128,564,6741,085,00002,113,536