Question

Python3: Write the function findLongestStreak(lst) which takes a list of numbers, lst, and returns the longest streak of numbers which occur in the list. A streak of numbers is a list of numbers where each number is one greater than the one that occurred before it- for example, [4, 5, 6, 7]. So findLongestStreak([3, 4, 8, 2, 3, 4, 5, 7, 8, 9]) would return [2, 3, 4, 5]. If there is more than one streak with the longest length, return the first one that occurs in the list.

Restrictions: for loop, 'in' key word, slicing, lambda function cannot be used.

It is recommended to use while loop to solve this problem

Answer 1

# do comment if any problem arises

# do thumbs up if it helps

# this function returns longest streak in given list

def findLongestStreak(lst):

# this is temprary variable to current list which is longest streak

current = [lst[0]]

# this is return variable which holds longest streak named prev ie previous longest streak

prev = []

# length is length of given lst

length = len(lst)

# initiailise i to 1 this variable is to create a while loop till length of given list

i = 1

while i != length:

# if current element is one greater than previous element

if(lst[i] == 1+lst[i-1]):

# append current element to current list

current.append(lst[i])

# else if length of previous longest streak is less than current streak

# copy current list to previous list

else:

if(len(prev) < len(current)):

n = len(current)

j = 0

prev=[]

while j != n:

prev.append(current[j])

j += 1

# clear current list and append current element to this list

current=[]

current.append(lst[i])

# increment i

i += 1

# if length of previous longest streak is less than current streak

# copy current list to previous list

# this case works if last element is included in longest streak

if(len(prev) < len(current)):

n = len(current)

j = 0

prev=[]

while j != n:

prev.append(current[j])

j += 1

return prev

# testing above function

print(findLongestStreak([3, 4, 8, 2, 3, 4, 5, 7, 8, 9]))

Screenshot of code:

Output: