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 8, 2026 07:43highload-churnerhighload-churnerScore: 1,957Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Nov 8, 2026 07:441,56011,038,867624,000020,480
2Nov 8, 2026 07:441,5729,599,201629,000020,480
3Nov 8, 2026 07:441,6059,971,981642,000020,480
4Nov 8, 2026 07:441,9559,801,421782,000020,480
5Nov 8, 2026 07:441,95710,155,627783,000020,480
6Nov 8, 2026 07:442,01710,053,930807,000020,480
7Nov 8, 2026 07:442,0479,772,977819,000020,480
8Nov 8, 2026 07:442,0559,848,996822,000020,480
9Nov 8, 2026 07:442,0609,947,264824,000020,480