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 listJul 1, 2026 05:59Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jul 1, 2026 06:0108,594,0941,134,00002,117,632expected "63", got "50 "stderr
2Jul 1, 2026 06:012,3428,366,113937,00002,117,632stderr
3Jul 1, 2026 06:012,4408,522,943976,00002,117,632stderr
4Jul 1, 2026 06:012,6908,700,8381,076,00002,117,632stderr
5Jul 1, 2026 06:012,7228,522,8321,089,00002,117,632stderr
6Jul 1, 2026 06:012,7278,634,3851,091,00002,117,632stderr
7Jul 1, 2026 06:012,7558,522,9211,102,00002,117,632stderr
8Jul 1, 2026 06:012,7708,553,9761,108,00002,117,632stderr
9Jul 1, 2026 06:012,8478,536,9971,139,00002,117,632stderr