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 17:31Andrew EpsteinAndrew EpsteinScore: 3,052Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 13, 2026 17:492,7359,559,3961,094,00002,117,632
2Sep 13, 2026 17:492,78010,259,5061,112,00002,117,632
3Sep 13, 2026 17:492,94710,304,7451,179,00002,117,632
4Sep 13, 2026 17:493,04510,371,1061,218,00002,117,632
5Sep 13, 2026 17:493,05211,508,6211,221,00002,117,632
6Sep 13, 2026 17:493,09010,407,2351,236,00002,117,632
7Sep 13, 2026 17:493,11210,464,0631,245,00002,117,632
8Sep 13, 2026 17:493,1279,622,3131,251,00002,117,632
9Sep 13, 2026 17:493,16510,506,6091,266,00002,117,632