recursive.py

# 4. recursive_factorial — Uses recursion to find the factorial of an integer.

def recursive_factorial (n):
  if n<=1:
    return 1 
  else:
    return n * recursive_factorial(n-1)

print(recursive_factorial(3))
print(recursive_factorial(6))


# 5. recursive_deduplicate — Recursively removes all adjacent duplicate letters from a string.

def recursive_deduplicate(my_str,i=0):
  # if our string is empty or only has 1 thing, it's got no duplicates
  # if i is at the end of the string, no duplicates are left
  if len(my_str) <= 1 or i == len(my_str)-1:
    return my_str
  else:
    # str at current position is same as next position
    if my_str[i] == my_str[i+1]:
      return recursive_deduplicate(my_str[0:i]+my_str[i+1:],i)
    else:
      #no duplicate at current position, check next
      return recursive_deduplicate(my_str,i+1)
      
print(recursive_deduplicate("aaaa"))
print(recursive_deduplicate("aaba"))
print(recursive_deduplicate("apple"))
print(recursive_deduplicate(""))


# 6. recursive_reverse — Uses recursion to reverse a string.

def recursive_reverse(str, i=0):
#empty string case
  if len(str)==0:
    return ""

#base case
  elif i== len(str) -1:
    return str[0]

  else:
#recursive case
    return str[-1-i] + recursive_reverse(str,i+1)   

print(recursive_reverse("aaaa"))
print(recursive_reverse("aaba"))
print(recursive_reverse("apple"))
print(recursive_reverse(""))