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 06:09Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jul 1, 2026 06:1109,430,6161,724,00002,117,632expected "51", got "50 "stderr
2Jul 1, 2026 06:112,0058,177,356802,00002,117,632stderr
3Jul 1, 2026 06:112,1558,474,212862,00002,117,632stderr
4Jul 1, 2026 06:112,4178,590,441967,00002,117,632stderr
5Jul 1, 2026 06:112,6728,505,3221,069,00002,117,632stderr
6Jul 1, 2026 06:112,6878,439,7731,075,00002,117,632stderr
7Jul 1, 2026 06:114,3309,475,6011,732,00002,117,632stderr
8Jul 1, 2026 06:114,7909,332,2521,916,00002,117,632stderr
9Jul 1, 2026 06:114,8579,336,3421,943,00002,117,632stderr