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 08:51Andrew EpsteinAndrew EpsteinScore: 1,722Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Nov 6, 2026 08:531,6829,661,051673,000020,480
2Nov 6, 2026 08:531,6829,646,847673,000020,480
3Nov 6, 2026 08:531,6879,664,989675,000020,480
4Nov 6, 2026 08:531,7179,718,466687,000020,480
5Nov 6, 2026 08:531,7229,648,610689,000020,480
6Nov 6, 2026 08:532,1809,838,575872,000020,480
7Nov 6, 2026 08:532,2279,911,658891,000020,480
8Nov 6, 2026 08:532,32010,136,851928,000020,480
9Nov 6, 2026 08:532,3359,934,632934,000020,480