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 17, 2026 03:31Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 17, 2026 03:3208,911,0161,373,00002,113,536expected "57", got "50 "
2Jun 17, 2026 03:322,2078,267,407883,00002,113,536
3Jun 17, 2026 03:322,2178,137,041887,00002,113,536
4Jun 17, 2026 03:322,3328,313,300933,00002,113,536
5Jun 17, 2026 03:323,2328,699,3241,293,00002,113,536
6Jun 17, 2026 03:323,5728,772,3061,429,00002,113,536
7Jun 17, 2026 03:323,7458,940,2411,498,00002,113,536
8Jun 17, 2026 03:323,7808,776,6871,512,00002,113,536
9Jun 17, 2026 03:324,1829,110,7951,673,00002,113,536