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 listOct 20, 2026 03:51highload-churnerhighload-churnerScore: 1,795Success
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Oct 20, 2026 03:521,6609,527,848664,000020,480
2Oct 20, 2026 03:521,7759,729,304710,000020,480
3Oct 20, 2026 03:521,78210,066,445713,000020,480
4Oct 20, 2026 03:521,78510,059,832714,000020,480
5Oct 20, 2026 03:521,79510,028,137718,000020,480
6Oct 20, 2026 03:521,8109,602,272724,000020,480
7Oct 20, 2026 03:521,8109,640,313724,000020,480
8Oct 20, 2026 03:521,86710,076,194747,000020,480
9Oct 20, 2026 03:521,99510,066,202798,000020,480