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 18:32Kevin HeaveyKevin HeaveyScore: 1,817Success
Source Code

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

Challenge History

No challenges yet.

Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 26, 2026 18:361,7729,200,754709,000024,576
2Sep 26, 2026 18:361,8059,141,083722,000024,576
3Sep 26, 2026 18:361,8059,072,887722,000024,576
4Sep 26, 2026 18:361,8129,241,198725,000024,576
5Sep 26, 2026 18:361,8179,142,402727,000024,576
6Sep 26, 2026 18:361,8179,361,775727,000024,576
7Sep 26, 2026 18:361,8309,209,742732,000024,576
8Sep 26, 2026 18:361,8409,239,965736,000024,576
9Sep 26, 2026 18:361,8429,294,602737,000024,576