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 20:15Kevin HeaveyKevin HeaveyScore: 2,002Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 25, 2026 20:161,9659,430,889786,000020,480
2Sep 25, 2026 20:161,9679,217,319787,000020,480
3Sep 25, 2026 20:161,9759,197,048790,000020,480
4Sep 25, 2026 20:162,0029,276,328801,000020,480
5Sep 25, 2026 20:162,00211,154,897801,000020,480
6Sep 25, 2026 20:162,0059,804,516802,000020,480
7Sep 25, 2026 20:162,0129,338,913805,000020,480
8Sep 25, 2026 20:162,0559,834,309822,000020,480
9Sep 25, 2026 20:162,3159,677,074926,000020,480