The word algorism, came from the 9^th century Persian mathematician "Abu Abdullah Muhammad bin Musa
   al-Khwarizmi" , which means the method of doing arithmetic using Indo-Arabic decimal system. It is also the
   root of the word "algorithm" .

  An algorithm is a well defined computational method that takes some value(s) as input and produce some        value(s) as output. In other words, an algorithm is a sequence of computational steps that transforms input(s)
   into output(s).

  An algorithm is correct if for every input, it halts with correct output. A correct algorithm solves the given
   problem,  where as an incorrect algorithm might not halt at all on some input instance, or it might halt with
   other than  designed answer.

Each algorithm must have

• Specification: Description of the computational procedure.
•  Pre-conditions: The condition(s) on input.

• Body of the Algorithm: A sequence of clear and unambiguous instructions.
• Post-conditions: The condition(s) on output.