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 13, 2026 19:57Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 13, 2026 19:5808,284,8761,216,00002,113,536expected "53", got "50 "
2Jun 13, 2026 19:582,4808,155,076992,00002,113,536
3Jun 13, 2026 19:582,5958,194,3931,038,00002,113,536
4Jun 13, 2026 19:582,6028,219,5761,041,00002,113,536
5Jun 13, 2026 19:582,7808,346,7571,112,00002,113,536
6Jun 13, 2026 19:582,9178,285,1371,167,00002,113,536
7Jun 13, 2026 19:582,9608,287,9241,184,00002,113,536
8Jun 13, 2026 19:583,0058,404,6941,202,00002,113,536
9Jun 13, 2026 19:583,0728,355,8601,229,00002,113,536