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 19:50Kevin HeaveyKevin HeaveyError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 26, 2026 19:52021,522,441588,000024,576Exit with code 3: mounts=2 Seccomp: 2 NoNewPrivs: 1 Cpus_allowed_list: 1 CapEff: 0000000000000000 285 261 9:2 /tmp/solution203193618/.sbox / rw,relatime - ext4 /dev/md2 rw|262 285 0:45 / /proc rw,relatime - proc proc rw,hidepid=invisible,subset=pid|stderr