Question

Solving Problems Using Recursion (Python):

To solve the problem, you have to use recursion and cannot use for or while loops to solve the problems as well as not using global variables.

3. Create a function that takes to strings and removes the similar letters from the longer one once.

Ex.

Input = "at" "radiator"

Output = "rdiaor"

notice how only the leftmost a was removed by the function

Answer 1

def remove_string(a, b):            #functin definition
    if len(a) == 0:         #termination condition when length of shorter one becomes zero
        return b            #retruning string after removing shorter one
    else:
        if a[0] in b:       #if letter is present in longer string
            b = b.replace(a[0], '', 1)
            return remove_string(a[1:], b)          #recursive call
        else:               #if letter is not present in the string
            return remove_string(a[1:], b)          #recursive call

str1, str2 = input('Enter the two strings(space separated): ').split()      #taking user input
if len(str1) > len(str2):       #checking for longer among two
    print(remove_string(str2, str1))        #calling the function
else:
    print(remove_string(str1, str2))

Screenshot of output: