Write a function revstring(mystr) that uses a stack to reverse the characters in a string. Save & RunShow FeedbackShow CodetestEqual(revstring('1234567890'),'0987654321') 1from test import testEqual2from pythonds.basic import Stack3​4def revstring(mystr):5 # your code here6​7testEqual(revstring('apple'),'elppa')8testEqual(revstring('x'),'x')9testEqual(revstring('1234567890'),'0987654321')10​

outputstr = ''
while not sta.isempty(): 
    outputstr = outputstr + sta.pop()
return outputstr

Given a list of numbers in random order, write an algorithm that works in O(nlog⁡(n)) to find the kth smallest number in the list.

for i in range(k, len(l)): 
    if l[i] < kl[ind]:
        kl[ind] = l[i]
        ind = findLargestIndex(kl)

return kl[ind]

Devise an experiment to verify that get item and set item are O(1) for dictionaries.

Devise an experiment to verify that the list index operator is

Give the Big-O performance of the following code fragment:

Give the Big-O performance of the following code fragment:

Give the Big-O performance of the following code fragment:

Give the Big-O performance of the following code fragment:

Give the Big-O performance of the following code fragment: