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 07:58Andrew EpsteinAndrew EpsteinScore: 2,182Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Nov 6, 2026 08:001,6729,685,362669,000020,480
2Nov 6, 2026 08:001,6829,657,761673,000020,480
3Nov 6, 2026 08:001,6909,655,147676,000020,480
4Nov 6, 2026 08:001,7109,658,950684,000020,480
5Nov 6, 2026 08:002,1829,851,458873,000020,480
6Nov 6, 2026 08:002,20510,328,033882,000020,480
7Nov 6, 2026 08:002,25011,694,188900,000020,480
8Nov 6, 2026 08:002,2629,911,020905,000020,480
9Nov 6, 2026 08:002,3159,977,863926,000020,480