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 05:17highload-churnerhighload-churnerError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Oct 20, 2026 05:1709,739,045697,000020,480expected "50", got "st54_tr95_mm132_ma61_fa160_gp23_50............. "
2Oct 20, 2026 05:17010,045,491708,000020,480expected "100", got "st58_tr98_mm121_ma58_fa164_gp23_50............. "
3Oct 20, 2026 05:17010,027,463714,000020,480expected "50", got "st58_tr89_mm148_ma62_fa162_gp22_50............. "