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 06:10Andrew EpsteinAndrew EpsteinScore: 2,195Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Nov 6, 2026 06:121,6909,599,390676,000020,480
2Nov 6, 2026 06:121,71711,557,217687,000020,480
3Nov 6, 2026 06:122,0859,720,609834,000020,480
4Nov 6, 2026 06:122,1329,862,967853,000020,480
5Nov 6, 2026 06:122,19510,354,070878,000020,480
6Nov 6, 2026 06:122,2009,900,671880,000020,480
7Nov 6, 2026 06:122,2209,867,448888,000020,480
8Nov 6, 2026 06:122,2409,881,044896,000020,480
9Nov 6, 2026 06:122,26210,363,743905,000020,480