Largest Square Submatrix of all 1's Haha Expert

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 listSep 13, 2026 21:32Andrew EpsteinAndrew EpsteinScore: 1,965Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 13, 2026 21:341,8878,910,785755,000020,480
2Sep 13, 2026 21:341,9008,992,772760,000020,480
3Sep 13, 2026 21:341,9158,972,216766,000020,480
4Sep 13, 2026 21:341,9459,029,336778,000020,480
5Sep 13, 2026 21:341,9658,993,581786,000020,480
6Sep 13, 2026 21:341,9679,012,262787,000020,480
7Sep 13, 2026 21:341,9929,049,014797,000020,480
8Sep 13, 2026 21:342,09520,717,776838,000020,480
9Sep 13, 2026 21:342,3459,197,704938,000020,480