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 listNov 6, 2026 05:29Andrew EpsteinAndrew EpsteinScore: 2,240Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Nov 6, 2026 05:311,7059,581,889682,000020,480
2Nov 6, 2026 05:311,7609,596,663704,000020,480
3Nov 6, 2026 05:311,9879,805,260795,000020,480
4Nov 6, 2026 05:312,1659,820,479866,000020,480
5Nov 6, 2026 05:312,2409,977,347896,000020,480
6Nov 6, 2026 05:312,25510,382,611902,000020,480
7Nov 6, 2026 05:312,26010,297,694904,000020,480
8Nov 6, 2026 05:312,2809,819,743912,000020,480
9Nov 6, 2026 05:312,3359,920,231934,000020,480