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 23:13Victor MerckléVictor MerckléError
Source Code

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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 16, 2026 23:1408,672,4671,165,00002,113,536expected "60", got "50 "
2Jun 16, 2026 23:1408,881,9771,192,00002,113,536expected "68", got "50 "
3Jun 16, 2026 23:1408,803,4601,200,00002,113,536expected "66", got "50 "
4Jun 16, 2026 23:142,5958,461,6801,038,00002,113,536
5Jun 16, 2026 23:142,7628,550,9531,105,00002,113,536
6Jun 16, 2026 23:142,9378,396,8131,175,00002,113,536
7Jun 16, 2026 23:143,0858,652,8361,234,00002,113,536
8Jun 16, 2026 23:143,1278,490,6931,251,00002,113,536
9Jun 16, 2026 23:143,2008,519,5241,280,00002,113,536