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 6, 2026 07:45Andrew EpsteinAndrew EpsteinScore: 2,245Success
Source Code

Source code access is restricted. Log in to request access.

Challenge History

No challenges yet.

Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Nov 6, 2026 07:471,7009,683,411680,000020,480
2Nov 6, 2026 07:471,7159,749,777686,000020,480
3Nov 6, 2026 07:472,1579,872,228863,000020,480
4Nov 6, 2026 07:472,1759,848,329870,000020,480
5Nov 6, 2026 07:472,2459,995,499898,000020,480
6Nov 6, 2026 07:472,2679,945,963907,000020,480
7Nov 6, 2026 07:472,30510,010,308922,000020,480
8Nov 6, 2026 07:472,3379,909,343935,000020,480
9Nov 6, 2026 07:472,70010,118,2661,080,000020,480