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 20:03Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 8, 2026 20:0408,616,6441,134,00002,113,536expected "54", got "50 "
2Jun 8, 2026 20:0408,589,8391,134,00002,113,536expected "80", got "50 "
3Jun 8, 2026 20:042,4559,747,652982,00002,113,536
4Jun 8, 2026 20:042,5478,510,3891,019,00002,113,536
5Jun 8, 2026 20:042,5578,501,7671,023,00002,113,536
6Jun 8, 2026 20:042,5958,631,4701,038,00002,113,536
7Jun 8, 2026 20:042,6208,535,6761,048,00002,113,536
8Jun 8, 2026 20:042,68710,030,0851,075,00002,113,536
9Jun 8, 2026 20:042,9778,754,9991,191,00002,113,536