1. Toeplitz Matrix

Follow ups: http://www.1point3acres.com/bbs/thread-195331-1-1.html

1. If we do not have enough memory to load the whole matrix but at least one line
2. If we cannot even read one line into memory, but small probability of incorrectness is allowed
   1. Rolling Hash, the hash value of the next line can be calculated by shifting the hash value of current line to the right by 1

Need to process twice, first the upper right triangle, then the lower left triangle.