פתרונות בקוד לבעיות
הוראות המופיעות בגוף של מבנה while ומתבצעות כל עוד תנאי הלולאה מתקיים צריכות להיות מוזזות ימינה ביחס לשורה הראשונה במבנה. הקוד התקין:
age = input(‘Insert age; -1 to stop: ‘)
while age != ‘-1’:
print(age)
age = input(‘Insert age; -1 to stop: ‘)
בעיה א’
• פתרון ראשון –
def deleteStrings(lst):
lst = lst[:]
newLst = []
for item in lst:
if type(item) != str:
newLst.append(item)
return newLst
• פתרון שני –
def deleteStrings(lst):
lst = lst[:]
i = 0
while i < len(lst):
item = lst[i]
if type(item) == str:
lst.remove(item)
else:
i += 1
return lst
• פתרון שלישי –
def deleteStrings(lst):
lst = lst[:]
for i in range(len(lst) – 1, -1, -1):
if type(lst[i]) == str:
del lst[i]
return lst
בעיה ב’
(א)
s1 = “Christmas without presents.”
s2 = “Christmas won’t be Christmas without any presents.”
i = 0
found = False
while i < len(s1) and not found:
substring = s1[:i]
if substring not in s2:
print(substring)
found = True
continue
i = i + 1
(ב)
s1 = “Christmas without presents.”
s2 = “Christmas won’t be Christmas without any presents.”
found = False
for i in range(1, len(s1) + 1):
for j in range(len(s1)):
substring = s1[j:j+i]
if len(substring) == i and substring not in s2 and not found:
print(substring)
found = True
(ג)
def findShortest(s1, s2):
for i in range(1, len(s1) + 1):
for j in range(len(s1)):
substring = s1[j:j+i]
if len(substring) == i and substring not in s2:
return substring
בעיה ג’
פתרון א’
def sortPositives(nums):
positiveNums = []
for num in nums:
if num > 0:
positiveNums.append(num)
positiveNums.sort()
j = 0
for i in range(len(nums)):
if nums[i] > 0:
nums[i] = positiveNums[j]
j += 1
return nums
פתרון ב’
def sortPositives(nums):
positiveNums = []
inds = []
for i in range(len(nums)):
if nums[i] > 0:
inds.append(i)
positiveNums.append(nums[i])
positiveNums.sort()
for i in range(len(positiveNums)):
nums[inds[i]] = positiveNums[i]
return nums
בעיה ד’
פתרון א’
def multipleAndConsecutive(s):
chars = set()
for char in set(s):
times = s.count(char)
if times > 1 and char * times in s:
chars.add(char)
return chars
פתרון ב’
def multipleAndConsecutive(s):
chars = set()
for char in set(s):
if s.count(char) >= 2:
consecutive = True
currentInd = s.find(char)
while currentInd != -1 and consecutive:
nextInd = s.find(char, currentInd + 1)
if (nextInd != -1 and
currentInd + 1 != nextInd):
consecutive = False
continue
currentInd = nextInd
if consecutive:
chars.add(char)
return chars
בעיה ה’
books = [‘1984’, ‘Dracula’, ‘Ulysses’, ‘Beloved’]
printed = []
for book1 in books:
for book2 in books:
for book3 in books:
if book1 != book2 and book2 != book3 and book1 != book3:
sortedTriad = sorted([book1, book2, book3])
if sortedTriad not in printed:
print([book1, book2, book3])
printed.append(sortedTriad)
בעיה ו’
def oneEligible(idsAndAges, maxSum):
itemsCopy = list(idsAndAges.items())
while itemsCopy:
key1, val1 = itemsCopy.pop()
for key2, val2 in itemsCopy:
if val1 + val2 <= maxSum:
del idsAndAges[key1]
del idsAndAges[key2]
return [[key1, key2], idsAndAges]
return [[], idsAndAges]
בעיה ז’
def game100(player1, player2):
import random
roundNum = 1
curPlayer = player1
nextPlayer = player2
points = {player1:0, player2:0}
while points[nextPlayer] <= 100:
cube1 = random.randint(1, 6)
cube2 = random.randint(1, 6)
if (cube1 == roundNum and cube2 == roundNum):
points[curPlayer] += 21
elif (cube1 == roundNum or cube2 == roundNum):
points[curPlayer] += playNum
curPlayer, nextPlayer = nextPlayer, curPlayer
roundNum = (roundNum + 1) % 7
return [points[curPlayer], curPlayer]
בעיה ח’
(א)
def numsFreq(nums):
return {num : nums.count(num) for num in set(nums)}
(ב)
def digitsFreq(nums):
d = {}
for num in nums:
digits = set(str(num))
for digit in digits:
intDigit = int(digit)
if intDigit not in d:
d[intDigit] = 1
else:
d[intDigit] += 1
return d
בעיה ט’
def mostActive(erruptions, measure):
mountains = {}
for erruption in erruptions:
if erruption[2] > measure:
if erruption[1] not in mountains:
mountains[erruption[1]] = 1
else:
mountains[erruption[1]] += 1
revMountains = [[freq, name] for name, freq in mountains.items()]
return sorted(revMountains, reverse = True)[0][1]
בעיה י’
def winners(types, choices):
choices = choices[:]
winners = set()
while sum(types) != 0 and choices:
applicant, typeInd = choices[0]
if types[typeInd] > 0:
types[typeInd] -= 1
winners.add(applicant)
del choices[0]
return sorted(list(winners))
בעיה י”א
def digitsAndNums(nums):
d = {}
for num in nums:
digits = set(str(num))
for digit in digits:
intDigit = int(digit)
if intDigit not in d:
d[intDigit] = [num,]
else:
d[intDigit] += [num]
for k in d:
d[k] = tuple(d[k])
return d
בעיה י”ב
import random
def game():
d = {}
stop = False
while not stop:
name = input(“Please enter name: “)
if (name == “end”):
stop = True
continue
computer = “enm”[random.randint(0, 2)]
player = input(“Please enter item: “)
winner = 0
if ((player == “n”) & (computer == “e”)
|
(player == “e”) & (computer == “m”)
|
(player == “m”) & (computer == “n”)
):
winner = 1
if name not in d.keys():
d[name] = [1, winner]
else:
d[name][0] += 1
d[name][1] += winner
return d
בעיה י”ג
(א)
def tableByInds(table, inds):
filteredDict = {}
for key, values in table.items():
filteredDict[key] = [values[ind] for ind in inds]
return filteredDict
(ב)
def filterTable(table, colName, values):
inds = []
for ind in range(len(table[colName])):
if table[colName][ind] in values:
inds.append(ind)
return tableByInds(table, inds)
(ג)
def sortTable(table, colname, rev = False):
valuesAndIndices=[[table[colname][ind], ind] for ind in range(len(table[colname]))]
valuesAndIndices = sorted(valuesAndIndices, reverse = rev)
return tableByInds([item[1] for item in valuesAndIndices], indsList)
בעיה י”ד
def insertWord(myDict, word):
key = word.count(‘a’)
if key not in myDict:
myDict[key] = [word]
else:
i = 0
while i < len(myDict[key]) and len(word) > len(myDict[key][i]):
i = i + 1
myDict[key].insert(i, word)
return myDict
בעיה ט”ו
def pricesDiffs(dicts):
alwaysSold = set(dicts[0].keys())
for d in dicts[1:]:
alwaysSold = alwaysSold & set(d.keys())
return {product : dicts[-1][product] – dicts[0][product] for product in alwaysSold}
בעיה ט”ז
(א)
def getPatientsDetails(patientsDict):
proceed = True
while proceed:
if (input(“Get details of a new patient (‘y’ or ‘n’)? “) == ‘y’):
hospitalName = input(“Enter hospital name: “)
patientCode = int(input(“patient code: “))
patientDetails = input(“Age, days, recovery status: “)
if patientsDict.get((hospitalName, patientCode), False):
print(“Patient’s details will be updated.”)
patientDetailsList = patientDetails.split(‘,’)
patientDetailsTuple = (int(patientDetailsList[0]),
int(patientDetailsList[1]),
eval(patientDetailsList[2]))
patientsDict[(hospitalName, patientCode)] = patientDetailsTuple
else:
proceed = False
return patientsDict
(ב)
def recoveryByHospital(patientsDict, recovered = 1):
hospitalNames = {key[0] for key in patientsDict}
results = []
for name in sorted(hospitalNames):
numOfRecoveries = 0
patientsNum = 0
for k, v in patientsDict.items():
if k[0] == name:
patientsNum += 1
if v[2]: numOfRecoveries += 1
if (recovered == 1):
results.append([name, numOfRecoveries])
else:
results.append([name, patientsNum – numOfRecoveries])
return results
בעיה י”ז
def minimalText(filename, chars):
f = open(filename, “r”)
s = “”
ch = f.read(1)
while chars != {} and ch != “”:
s += ch
if ch in chars:
if chars[ch] == 1:
del chars[ch]
else:
chars[ch] -= 1
if not chars:
return s
ch = f.read(1)
f.close()
return “”
בעיה י”ח
def produceCSVDict(filename):
f = open(filename)
s = f.read()
f.close()
csvDict = {}
lines = s.split(“\n”)
colnames = lines[0].split(“,”)
for line in lines[1:]:
words = line.split(“,”)
for i in range(len(words)):
if colnames[i] not in csvDict:
csvDict[colnames[i]] = [words[i]]
else:
csvDict[colnames[i]].append(words[i])
return csvDict
בעיה י”ט
def getFileString(filename):
f = open(filename, ‘r’)
s = f.read()
f.close()
return s
def getCleanFile(s, puncts):
s = s.lower()
newS = “”
for c in s:
if c not in puncts:
newS = newS + c
else:
newS = newS + ” “
return newS
def findWordsAndFreqs(text, wordFirst = True):
words = text.split()
wordsAndFreqs = ()
for word in set(words):
if wordFirst:
wordsAndFreqs += ((word, words.count(word)),)
else:
wordsAndFreqs += ((words.count(word), word),)
return wordsAndFreqs
def compareFreqs(filename1, filename2, puncts, exclude):
cleanText1 = getCleanFile(getFileString(filename1), puncts)
wordsAndFreq1 = findWordsAndFreqs(cleanText1, False)
sortedPairs = sorted(wordsAndFreq1, reverse = True)
nonExcluded = [pair for pair in sortedPairs if pair[1] not in exclude]
cleanText2 = getCleanFile(getFileString(filename2), puncts)
wordsAndFreq2 = findWordsAndFreqs(cleanText2)
freqsDict = dict(wordsAndFreq2)
result = ()
for freq, word in nonExcluded[:10]:
result += ((word, freq, freqsDict.get(word, “NA”)),)
return result
