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 5, 2026 23:22Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jul 5, 2026 23:2408,942,1131,584,00002,117,632expected "56", got "50 "stderr
2Jul 5, 2026 23:2409,119,7981,573,00002,117,632expected "54", got "50 "stderr
3Jul 5, 2026 23:242,3128,497,424925,00002,117,632stderr
4Jul 5, 2026 23:242,4908,333,359996,00002,117,632stderr
5Jul 5, 2026 23:242,5028,607,0681,001,00002,117,632stderr
6Jul 5, 2026 23:242,66717,089,2851,067,00002,117,632stderr
7Jul 5, 2026 23:244,0409,014,2111,616,00002,117,632stderr
8Jul 5, 2026 23:244,1859,153,9451,674,00002,117,632stderr
9Jul 5, 2026 23:244,2709,213,7711,708,00002,117,632stderr