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 10:27Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 16, 2026 10:2908,506,3601,391,00002,113,536expected "60", got "50 "
2Jun 16, 2026 10:292,3678,052,291947,00002,113,536
3Jun 16, 2026 10:292,3958,119,147958,00002,113,536
4Jun 16, 2026 10:292,7758,143,4781,110,00002,113,536
5Jun 16, 2026 10:293,3928,465,5341,357,00002,113,536
6Jun 16, 2026 10:293,4828,598,3811,393,00002,113,536
7Jun 16, 2026 10:293,5528,589,7831,421,00002,113,536
8Jun 16, 2026 10:293,5608,598,6361,424,00002,113,536
9Jun 16, 2026 10:293,5928,612,6591,437,00002,113,536