• oct_to_dec - convert octal numbers to decimal
• hex_to_sept - convert hexadecimal numbers to septenary. Here I'm use functions to_dec() and from_dec() that usable for any numeral systems.

Here we have program with class Numbers that realizes summation, subtraction and multiplication for numbers with any numeral systems from 2 to 256. Each digit of number which we work presented as separated element of list, so it's kinda of realization of arbitrary-precision arithmetic.

We consider O-notation, and calculate processing time of following algorithms: insertion sort, selection sort and combining of two arrays.