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 07:43Andrew EpsteinAndrew EpsteinScore: 2,192Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Nov 6, 2026 07:451,7079,934,332683,000020,480
2Nov 6, 2026 07:452,1329,886,848853,000020,480
3Nov 6, 2026 07:452,1809,907,859872,000020,480
4Nov 6, 2026 07:452,1859,923,637874,000020,480
5Nov 6, 2026 07:452,1929,931,013877,000020,480
6Nov 6, 2026 07:452,2009,880,567880,000020,480
7Nov 6, 2026 07:452,2109,934,214884,000020,480
8Nov 6, 2026 07:452,2359,933,980894,000020,480
9Nov 6, 2026 07:452,2359,995,049894,000020,480