What is Iteration

The main advantage of a Recursive Algorithm (an algorithm defined in terms of itself) is that it can be easily described and easily implemented in a programming language (van Breughel, 1997). On the other hand, the efficiency of such an algorithm is relatively low because for every recursive call not yet terminated, a number of data should be maintained in a stack, causing time delays and requiring higher memory space (Rohl, 1984). Solving the same problem iteratively instead of recursively can improve time and space efficiency. For example, to solve a problem that involves N recursive procedure calls, it will require stack space linear to N. On the contrary, using iteration, the program will need a constant amount of space, independent of the number of iterations. There are programming languages, such as Prolog, that do not possess built-in iterative structures and so recursion should be used instead. Nevertheless, there are ways to write recursive programs that have similar behaviour with that of the corresponding iterative programs.