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 8, 2026 06:52highload-churnerhighload-churnerScore: 1,650Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Nov 8, 2026 06:531,61210,035,624645,000020,480
2Nov 8, 2026 06:531,6329,639,390653,000020,480
3Nov 8, 2026 06:531,63210,044,771653,000020,480
4Nov 8, 2026 06:531,6509,692,750660,000020,480
5Nov 8, 2026 06:531,6509,664,212660,000020,480
6Nov 8, 2026 06:532,0209,850,328808,000020,480
7Nov 8, 2026 06:532,0409,834,144816,000020,480
8Nov 8, 2026 06:532,0579,918,176823,000020,480
9Nov 8, 2026 06:532,0829,861,181833,000020,480