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 08:03Andrew EpsteinAndrew EpsteinScore: 2,227Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Nov 6, 2026 08:061,6979,580,421679,000024,576
2Nov 6, 2026 08:061,7209,525,859688,000024,576
3Nov 6, 2026 08:061,7459,555,624698,000024,576
4Nov 6, 2026 08:062,1659,746,701866,000024,576
5Nov 6, 2026 08:062,2279,790,680891,000024,576
6Nov 6, 2026 08:062,2309,749,658892,000024,576
7Nov 6, 2026 08:062,2659,850,254906,000024,576
8Nov 6, 2026 08:062,2709,872,345908,000024,576
9Nov 6, 2026 08:062,36015,903,245944,000024,576