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 5, 2025 01:43zielajzielajScore: 3,642Success
Source Code

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Challenge History
DateChallengerCostTypeStatus
Apr 27, 2026 15:38Victor Mercklé12.83RecheckSolution Held
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 5, 2025 01:432,99322,220,70801,197,0002,486,272
2Jun 5, 2025 01:433,02319,077,3301,209,00002,486,272
3Jun 5, 2025 01:433,19316,018,8161,277,00002,490,368
4Apr 27, 2026 15:393,64023,393,81601,456,0002,494,464
5Apr 27, 2026 15:393,64214,736,95701,457,0002,482,176
6Apr 27, 2026 15:393,91720,865,2441,567,00002,486,272