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 listJan 1, 2026 16:27Josu San MartinJosu San MartinScore: 5,320Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jan 1, 2026 16:275,18019,659,2851,036,0001,036,0002,441,216
2Jan 1, 2026 16:275,21516,508,2651,043,0001,043,0002,437,120
3Jan 1, 2026 16:275,21518,462,8131,043,0001,043,0002,445,312
4Jan 1, 2026 16:275,31519,115,7721,063,0001,063,0002,449,408
5Jan 1, 2026 16:275,32023,850,3921,064,0001,064,0002,445,312
6Jan 1, 2026 16:275,38017,566,1101,076,0001,076,0002,449,408
7Jan 1, 2026 16:275,43519,035,0341,087,0001,087,0002,449,408
8Jan 1, 2026 16:275,45521,451,2861,091,0001,091,0002,449,408
9Jan 1, 2026 16:275,50017,974,8341,100,0001,100,0002,449,408