CompSci 101 Sec01 Spring 2015 Solution

1A. 
Output              NOTES on output
<type 'float'>
1                   multiplication occurs first, then the subtraction 
                      7 - 6  is 1
False               7 <= 2 is false
4                   7 squared is 49,  49/10 with integer division is 4
2                   14 % 6, 6 goes into 14 twice with 2 remaining  

1B.
s                   s is in slot 2 of "Was" - note W is in slot 0
shi                 note pos is 5, so this is city[2:5], which is 
                      the characters in slots 2 through 4
ton                -3 means the last three characters from the right end of
                      the string
Cary               the last ciy in the list
['Atlanta', 'Washington']      The cities in slot 1 and 2

2A. 
def ConvertRupeesToDollars(amount, charge, rate):
    return amount * rate - charge/100*amount * rate

Alternate Solution:
def ConvertRupeesToDollars(amount, charge, rate):
    total = amount * rate
    fee = charge/100 * total
    return total - fee

2B. 
def hotelStay(price, days, tax, fee): 
    # calculate fee based on days
    if days > 6:             
        fee = 0 
    elif days > 3: 
        fee = fee/2.0 
    total = price * days    # calculate total price
    totalPlusTax = total* (1 + tax/100.0)   # add tax
    return totalPlusTax + fee* days        # add fee


3A. 
Q1. It does not work correctly for any of these:
remove(data, 'follow')
remove(data, 'fruit')
Note 'brown' gives the correct answer

Q2. It does not add the word to the list if the first letter matches but
the second letter does not match, but should add that word.

Q3. 
def removeCorrect(alist, testword):
    answer = []
    for word in alist:
        if word[0] == testword[0]:
            if word[1] == testword[1]:
                pass
            else:
                answer = answer + [word]
        else:
            answer = answer + [word]
    return answer

Alternate Soln:

def removeCorrect2(alist, testword):
    answer = []
    for word in alist:
        if word[0] == testword[0] and word[1] == testword[1]:
                pass
        else:
            answer = answer + [word]
    return answer

Alternate Soln:

def removeCorrect3(alist, testword):
    answer = []
    for word in alist:
        if word[0] != testword[0] or word[1] != testword[1]:
            answer = answer + [word]
    return answer

3B.
B1. people, key

B2. names, "er"

B3. ['Karler', 'Bether', 'Frederick', 'Saraher', 'Bruceer']

B4. []

B5. Mystery crashes since y[0] does not exist

B6. Mystery first looks at every word in the list and if any word does not have
key in the word it adds it to the right end of the word. Then it creates a
new list of those words in which the key appears starting in one of the
first four positions. It returns the first such word. 

B7. The example given crashes it. 
Another example would be mystery(names, 'only')


4A. 
def posUpper(word):
    for i in range(len(word)):
        if word[i] == word[i].upper():
            return i 
    return -1

4B.
def posSecondUpper(word):
    pos1 = posUpper(word)
    if pos1 == -1:
        return -1
    pos2 = posUpper(word[pos1+1:]) 
    if pos2 == -1:
        return -1
    else:
        return pos1 + pos2 +1
    
4C.
def emphasize(word):
    pos1 = posUpper(word)
    pos2 = posSecondUpper(word)
    if pos1 == -1:  # no uppercase letters
        return word.upper()
    if pos2 == -1:  # only one uppercase letter
        return word[:pos1+1] + "ly" + word[pos1+1:]
    # at least two uppercase
    return word[:pos1] + word[pos1] + word[pos1] + word[pos1+1:pos2+1] + "ly" + word[pos2+1:]

5A. 
def playersFrom(data,school):
    answer = []
    for line in data:
        alist = line.split("#")
        if alist[2] == school:  
            answer = answer +[alist[0]]
    return answer

#Alternate solution with append

def playersFrom(data,school):
    answer = []
    for line in data:
        alist = line.split("#")
        if alist[2] == school:  
            answer.append(alist[0])
    return answer

5B.
def playersOfTypes(data,year1,year2):
    answer = []
    for line in data:
        alist = line.split("#")
        if alist[1] == year1 or alist[1] == year2:  
            answer = answer +[alist[0]+ "-" + alist[2]]
    return answer        

#Alternate solution with append

def playersOfTypes(data,year1,year2):
    answer = []
    for line in data:
        alist = line.split("#")
        if alist[1] == year1 or alist[1] == year2:  
            answer.append(alist[0]+ "-" + alist[2])
    return answer