http://dongdli.wordpress.com/2013/05/21/codes-of-the-function-int-asctoint-const-char-num/ Codes from SECTION_B DONG LI
http://xplaux.wordpress.com/2013/05/22/minor-changes-to-dongdlis-code/ - A couple changes were made in regards to variable declaration in the for loop and simplifying an if condition. (Philip Lau - Section A)