Question

can anyone share their PS3 part 1 results? I created a working function fine but don't know the difference between recursive and iterative functioning. If you have an example of both it would be great.

Answer 1

An iterative function will repeat itself through a list, like
mylist = [milk, bread, eggs]
so any defined function will first test on "milk", then test on "bread", then test on "eggs." Then it will be done.
Conversely, the process of a function calling itself is recursion. Here's an example:
def nLines(n):
...if n > 0:
...print
...nLines(n-1)
So this function calls itself and modifies the variable "n" each time, rather than running through a preset list as an iterative function would.

I'm still on ps1, but hopefully that helps you.

Answer 2

Yuk- that's ugly. Sorry, look here for the little code I rendered illegible above:
http://dpaste.com/606899/

Answer 3

def countSubStringMatch(target, key):
counted = 0
i = 0
nextindex = 0
while i != -1:
nextindex = i + len(key)
i = target.find(key, nextindex)
counted += 1
return counted

def countSubStringMatchRecursive(target, key):
if target.find(key) == -1:
return 0
else:
nextindex = target.find(key) + len(key)
return 1 + countSubStringMatchRecursive(target[nextindex:], key)

Answer 4

countSubStringMatch(target, key) is an iterative function; using a loop construct to repeat a detailed process a described number of times characterizes an iterative function. This is the main style used in the imperative/procedural programming paradigm.

countSubStringMatchRecursive(target, key) is a recursive function; a function that breaks down a larger problem into a smaller problem by calling itself is an important characteristic of recursive functions. This is the main style used by the functional/declarative programming paradigm.