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 8, 2026 20:28Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 8, 2026 20:2908,498,319974,00002,113,536expected "55", got "50 "
2Jun 8, 2026 20:2908,436,651894,00002,113,536expected "61", got "50 "
3Jun 8, 2026 20:2908,385,481968,00002,113,536expected "87", got "50 "
4Jun 8, 2026 20:291,7308,313,645692,00002,113,536
5Jun 8, 2026 20:291,9708,284,794788,00002,113,536
6Jun 8, 2026 20:291,9808,289,432792,00002,113,536
7Jun 8, 2026 20:292,4278,397,855971,00002,113,536
8Jun 8, 2026 20:292,4708,445,171988,00002,113,536
9Jun 8, 2026 20:292,4878,512,488995,00002,113,536