CompSci 101 Sec 1 Test 2 Spring 2016 Solution

PROBLEM 1
PART 1A
0 X
1 A
2 G
['X', 'A', 'G', 'R']
['X', 'A', 'B', 'G']
---------------------
set(['A', 'H', 'D'])
['A', 'D', 'H', 'P']
---------------------
set([1, 6])
set([1, 2, 3, 4, 6, 7])
set([2, 3])
---------------------
5
['B', 'F', 'J', 'K', 'S']
[3, 5, 6, 6, 12]

PART 1B
['s', 'r', 'c', 'd']
[3, 1, 2, 1]
3
s

PROBLEM 2
PART 2A:
['money', 'sassy', 'yes']

PART 2B:
[('s', 'star'), ('s', 'yes'), ('sss', 'sassy')]

PART 2C:
temp = [w for w in words if len(w) > len(words[0])]

PART 2D:
temp = sorted([w for w in words if w[0] == 's']) + 
   sorted([w for w in words if w[0] != 's'])

ALT SOLN:
temp = sorted([w for w in words if w[0] == 's'])
second =  sorted([w for w in words if w[0] != 's'])
for w in second:
    temp.append(w)

ALT SOLN
temp = sorted([w for w in words if w[0] == 's'])
second =  sorted([w for w in words if w[0] != 's'])
temp.extend(second)

PART 2E:
def modify(namelist):
    return [' '.join([w.split()[1], w.split()[0]]) for w in names if
             len(w.split()) == 2]

ALT SOLN:
def modify(namelist):
    answer = []
    for w in names:
        words = w.split()
        if len(words) == 2:
            answer.append(" ".join([words[1], words[0]]))
    return answer

PROBLEM 3:

PART 3A
def processData(filename):
    f = open(filename)
    answer = []
    for line in f:
        alist = line.strip().split("/")
        answer.append(alist)
    f.close()
    return answer
    
PART 3B    
def coursesWaitlisted(filename, name):
    datalist = processData(filename)
    clist = []
    for items in datalist:
        course = items[0]
        last = items[1]
        limit = int(items[2])
        pos = int(items[3])
        if last == name and pos > limit:
            clist.append((pos-limit, course))  
    return clist  

ALT SOLN:    
def coursesWaitlisted2(filename, name):
    datalist = processData(filename)
    d = {}
    for key in datalist:
        num = int(key[3]) - int(key[2])
        if num > 0:
            if key[1] not in d:
                d[key[1]] = [(num, key[0])]
            else: 
                d[key[1]].append((num,key[0]))
    return d[name]    


PROBLEM 4
PART 4A
# Unique names of people
def UniqueNames(datalist):
    answer = set([])
    for item in datalist:
        answer.add(item[1])
    return sorted(list(answer))

ALT Soln

def UniqueNames(datalist):
    answer = []
    for item in datalist:
        if item[1] not in answer:
            answer.append(item[1])
    return sorted(answer)

PART 4B
# unique states with someone age or older            
def UniqueStatesByAge(datalist, age):    
    answer = set([])
    for item in datalist:
        if int(item[2]) >= age:
            answer.add(item[0])
    return sorted(list(answer))

PART 4C

# given a list of states we advertised in.
# which states did we advertise in and sold something?
def StatesSoldIn(datalist, advertised):
    alllist = set([])
    for item in datalist:
        alllist.add(item[0])
    allad = set(advertised)
    return sorted(list(alllist & allad))

ALT SOLN:
def StatesSoldIn(datalist, advertised):
    answer = []
    for item in datalist:
        state = item[0]
        if state not in answer:
            if state in advertised:
                answer.append(state)
    return sorted(answer)


PART 4D

def MostCardsSoldInState(datalist):
    d = {}
    for item in datalist:
        key = item[0]
        count = int(item[3])
        if key not in d:
            d[key] = count
        else:
            d[key] += count
    print d
    return max(d.values())

ALT SOLN:
def MostCardsSoldInState(datalist):
    d = {}
    for item in datalist:
        key = item[0]
        count = int(item[3])
        if key not in d:
            d[key] = count
        else:
            d[key] += count
    print d
    maxvalue = 0
    for v in d.values():
        if v > maxvalue:
            maxvalue = v
    return maxvalue


PART 4E    
    
def StateWithMostAges(datalist):
    d = {}
    for item in datalist:
        state = item[0]
        if state not in d:
            d[state] = [item[2]]
        else: 
            d[state].append(item[2])
    maxnum = max([len(set(w)) for w in d.values()])
    
    for (state,names) in d.items():
        if len(set(names)) == maxnum:
            return state    

ALT SOLN
def StateWithMostAges(datalist):
    d = {}
    for item in datalist:
        state = item[0]
        if state not in d:
            d[state] = set(item[2])
        else: 
            d[state].add(item[2])
    maxnum = 0
    maxstate = ""
    for (state,names) in d.items():
        if len(names) > maxnum:
            maxnum = len(names)
            maxstate = state
    return state