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 08:37Andrew EpsteinAndrew EpsteinScore: 2,267Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Nov 6, 2026 08:391,7659,737,798706,000020,480
2Nov 6, 2026 08:391,78010,713,524712,000020,480
3Nov 6, 2026 08:392,2159,929,716886,000020,480
4Nov 6, 2026 08:392,24210,343,966897,000020,480
5Nov 6, 2026 08:392,26710,379,047907,000020,480
6Nov 6, 2026 08:392,32010,395,962928,000020,480
7Nov 6, 2026 08:392,32710,392,700931,000020,480
8Nov 6, 2026 08:392,38510,442,259954,000020,480
9Nov 6, 2026 08:392,4029,925,159961,000020,480