CS 1MD3 - Winter 2006 - Assignment #2

Generated for Student ID: 0470107

Due Date: Wednesday, February 8th

(You are responsible for verifying that your student number is correct!)

Part 1: Debugging

The following four functions are infested with bugs. Correct them by adding or changing a single line in each one. Clearly indicate your changes with comments. If you add a line, append the comment, "# added." If you change a line, append a comment to it containing the original, erroneous line. Solutions submitted without comments will not be marked.

1

def deinterlaceEven(interlacedList):
	"""Returns a list consisting of only the even elements of the given list.
	For example, deinterlaceEven(['1', 'a', '2', 'b', '3', 'c']) returns [1,2,3]."""
	n = len(interlacedList)
	if n == 0:
		return None
	i = 0
	evenList = []
	while i < n:
	evenList.append(interlacedList[i])	
		i = i+2
	return evenList

def reverseList(aList):
	"""Reverses the elements of a list.  Yes, yes... Python has a built-in function
	to do that, but what if someone steals it?  Ha!  Bet you never thought of that,
	did ya??"""
	n = len(aList)
	i = 0
	while i < n/2:
		j = n-i+1	
		temp = aList[i]
		aList[i] = aList[j]
		aList[j] = temp
		i = i+1

def product(numberList):
	"""Computes the product of all the list elements."""
	n = len(numberList)
	if n <= 0:
		return None
	theProduct = 1
	i = n-1
	while i >= 0:
		theProduct = theProduct * numberList[i]
		i=i+1	
	return theProduct

def argMax(aList):
	"""Returns the index of the largest element in the list"""
	n = len(aList) 
	if n <= 0:
		return None
	i = 0
	theArgMax = i
	theMax = aList[theArgMax]
	while i < n:
		x = aList[i]
		if x > theMax:
			Max = x	
			theArgMax = i
		i = i + 1
	return theArgMax

Part 2: Testing

Create automated tests for the following function using PyUnit. Your tests should ensure that the code produces the expected result in all cases.

def bubbleSort(aList):
	"""Sorts the given list using the (in)famous BubbleSort algorithm."""
	n = len(aList)
	i = 0
	while i < n-1:
		j = 0
		while j < n-i-1:
			if aList[j+1] < aList[j]:
				temp = aList[j]
				aList[j] = aList[j+1]
				aList[j+1] = temp
			j = j+1
		i = i+1