Largest Square Submatrix of all 1's NoSIMD_C#

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 listApr 27, 2026 13:20Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Apr 27, 2026 13:20035,382,284013,211,0002,367,488Exit with code 1: probe_v=input_size_1 stdin_regular=1 st_size=100000000 probe_v=input_size_1 stdin_regular=1 st_size=100000000 bytes_read=100000000 read_calls=97 eof_seen=1 elapsed_ms=11.585 first_read_ms=0.434 max_read_ms=0.434 mb_per_s_x1000=639289 ...stderr