Binary conversion issues
A hex
The first analysis of this question, two points, put a hex string into a decimal integer, the second traverse the entire string, beginning to find substring of 0x.
Title relatively simple, directly on the part of the code
16 hex 10 hex turn, may become changed by a slight modification applied to the other wheel int decimal binary string
Each 0x found, the new index, Hex substring is obtained after 0x
Second, the binary conversion
This problem with the opposite problem, into any decimal digit string
Very simple, performing a modulo operation, Euclidean algorithm operates directly on the code
Third, octal, decimal
This next question write it, before the code ugly, heavy wrote.