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 21:55Victor MerckléVictor MerckléScore: 5,697Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 16, 2026 21:562,6428,237,2151,057,00002,113,536
2Jun 16, 2026 21:562,7278,237,5441,091,00002,113,536
3Jun 16, 2026 21:562,8978,314,1201,159,00002,113,536
4Jun 16, 2026 21:562,9628,393,4251,185,00002,113,536
5Jun 16, 2026 21:565,6979,568,8192,279,00002,113,536
6Jun 16, 2026 21:566,1709,623,1222,468,00002,113,536
7Jun 16, 2026 21:566,4529,747,5332,581,00002,113,536
8Jun 16, 2026 21:5628,58718,599,65711,435,00002,113,536
9Jun 16, 2026 21:5671,57035,847,12928,628,00002,113,536