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 listOct 20, 2026 08:16highload-churnerhighload-churnerScore: 1,780Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Oct 20, 2026 08:181,58710,006,855635,000020,480
2Oct 20, 2026 08:181,70510,027,147682,000020,480
3Oct 20, 2026 08:181,77510,021,005710,000020,480
4Oct 20, 2026 08:181,7809,984,920712,000020,480
5Oct 20, 2026 08:181,78010,051,638712,000020,480
6Oct 20, 2026 08:181,79510,050,121718,000020,480
7Oct 20, 2026 08:181,7979,717,930719,000020,480
8Oct 20, 2026 08:181,80710,107,225723,000020,480
9Oct 20, 2026 08:182,0379,853,967815,000020,480