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 7, 2026 13:52Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 7, 2026 13:5308,346,2641,050,00002,113,536expected "100", got "50 "
2Jun 7, 2026 13:5308,266,9011,044,00002,113,536expected "52", got "50 "
3Jun 7, 2026 13:531,8958,134,743758,00002,113,536
4Jun 7, 2026 13:532,3708,324,469948,00002,113,536
5Jun 7, 2026 13:532,5608,234,7391,024,00002,113,536
6Jun 7, 2026 13:532,5808,240,1901,032,00002,113,536
7Jun 7, 2026 13:532,6178,345,9071,047,00002,113,536
8Jun 7, 2026 13:532,6508,249,9741,060,00002,113,536
9Jun 7, 2026 13:532,65711,016,5041,063,00002,113,536