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 17, 2026 09:06Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 17, 2026 09:0808,442,9991,245,00002,113,536expected "52", got "50 "
2Jun 17, 2026 09:081,8757,745,736750,00002,113,536
3Jun 17, 2026 09:081,9507,896,641780,00002,113,536
4Jun 17, 2026 09:082,2128,084,091885,00002,113,536
5Jun 17, 2026 09:082,5357,978,4631,014,00002,113,536
6Jun 17, 2026 09:083,2358,438,7391,294,00002,113,536
7Jun 17, 2026 09:083,2658,424,6601,306,00002,113,536
8Jun 17, 2026 09:083,5708,559,5051,428,00002,113,536
9Jun 17, 2026 09:083,5958,630,9661,438,00002,113,536