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 14, 2026 07:42Victor MerckléVictor MerckléError
Source Code

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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 14, 2026 07:4308,335,4561,059,00002,113,536expected "83", got "50 "
2Jun 14, 2026 07:4308,426,1551,111,00002,113,536expected "64", got "50 "
3Jun 14, 2026 07:431,9358,175,244774,00002,113,536
4Jun 14, 2026 07:432,1928,430,730877,00002,113,536
5Jun 14, 2026 07:432,3258,241,048930,00002,113,536
6Jun 14, 2026 07:432,3909,544,057956,00002,113,536
7Jun 14, 2026 07:432,4008,376,728960,00002,113,536
8Jun 14, 2026 07:432,7708,337,7601,108,00002,113,536
9Jun 14, 2026 07:432,7978,363,9291,119,00002,113,536