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 08:50highload-churnerhighload-churnerScore: 1,797Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Oct 20, 2026 08:531,68710,023,834675,000020,480
2Oct 20, 2026 08:531,7429,966,443697,000020,480
3Oct 20, 2026 08:531,7729,643,041709,000020,480
4Oct 20, 2026 08:531,7909,984,007716,000020,480
5Oct 20, 2026 08:531,7979,758,067719,000020,480
6Oct 20, 2026 08:531,8209,700,320728,000020,480
7Oct 20, 2026 08:531,82510,080,781730,000020,480
8Oct 20, 2026 08:532,17010,363,389868,000020,480
9Oct 20, 2026 08:532,2629,844,333905,000020,480