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 listSep 26, 2026 19:46Kevin HeaveyKevin HeaveyError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 26, 2026 19:49010,422,622570,000024,576Exit with code 3: self/sch=196463 1966 2 |self/sta=1 (main) R 0 0 0 0 -1 4194560 35 0 0 0 0 0 0 0 20 0 1 0 790031369 1314816 0 18446744073709551615 4194304 4600049 140721823797680 0 0 0 0 0 0 0 0 0 17 1 0 0 0 0 |self/sch=494676 1966 2 |stderr