CS 1MD3 - Winter 2006 - Assignment #2

Generated for Student ID: 0467208

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 argMin(aList):
	"""Returns the index of the smallest element in the list"""
	n = len(aList) 
	if n <= 0:
		return None
	i = 0
	theArgMin = i
	theMin = aList[theArgMin]
	while i < n:
		x = aList[i]
		if x < theMin:
			theMin = x
			theArgMin = i
		i = i + 1
		return theArgMin

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 = -i-1
		temp = aList[i]
		aList[i] = aList[j]
		aList[j] = tmp	
		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 = 1
	while i >= -n: 
		theProduct = theProduct * numberList[i]
		i=i-1
	return theProduct

def norm(aVector):
	"""Computes the Euclidian norm of the given vector in R^n.
	The Euclidean norm of x=(x1, x2, ..., xn) is defined as the square root of
	x1^2 + x2^2 + ... + xn^2."""
	n = len(aVector)
	if n <= 0:
		return None
	theNorm = 0
	i = 0
	while i < n:
		theNorm = theNorm + abs(aVector[i])**2
		i = i-1	
	return pow(theNorm, 0.5)

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 isAnagram(str1, str2):
	"""Returns True if the two strings are anagrams of each other (i.e. if str2 is 
	simply a permutation of the letters of str1); otherwise returns False."""
	if len(str1) != len(str2):
		return False
	list1 = list(str1)
	list2 = list(str2)
	n = len(list1)
	for x in list1:		# For each character in list1...
		if x in list2:	# ...if that character appears in list2, remove it from list2.
			xPos = list2.index(x)
			list2 = list2[0:xPos] + list2[xPos+1:len(list2)]
		else:
			return False	
	if len(list2) == 0:	# If list2 is empty by this point, then the strings were anagrams
		return True
	else:
		return False