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 25, 2026 20:43Kevin HeaveyKevin HeaveyScore: 1,810Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 25, 2026 20:441,7929,850,703717,000020,480
2Sep 25, 2026 20:441,7959,099,753718,000020,480
3Sep 25, 2026 20:441,8029,607,091721,000020,480
4Sep 25, 2026 20:441,8059,209,272722,000020,480
5Sep 25, 2026 20:441,8109,216,665724,000020,480
6Sep 25, 2026 20:441,8179,206,005727,000020,480
7Sep 25, 2026 20:441,8259,224,714730,000020,480
8Sep 25, 2026 20:441,8309,768,113732,000020,480
9Sep 25, 2026 20:441,8409,724,091736,000020,480