All done

part-1.py

@@ -4,17 +4,36 @@
 # the appropriate comment.
 
 # factorial
-
+def factorial(n):
+    if n == 0 or n == 1:
+        return 1
+    elif n < 0:
+        raise ValueError
+    else:
+        return n * factorial(n-1)
 
 
 # reverse
-
+def reverse(text):
+    if len(text) <= 1:
+        return text
+    return reverse(text[1::])+text[0]
 
 
 # bunny
-
+def bunny(count):
+    if count == 0:
+        return 0
+    else:
+        return 2+bunny(count-1)
 
 
 # is_nested_parens
-
+def is_nested_parens(parens):
+    if len(parens) %2:
+        return False
+    if parens == "":
+        return True
+    if parens[0] == "(" and parens[-1] == ")":
+        return is_nested_parens(parens[1:-1])
 

part-2.py

@@ -4,13 +4,38 @@
 # the appropriate comment.
 
 # search
-
+def search(array, query):
+    if not array:
+        return False
+    if array[0] == query:
+        return True
+    return search(array[1:], query)
 
 
 # is_palindrome
+def is_palindrome(text):
+    if len(text) <= 1:
+        return True
+    if text[0] != text[-1]:
+        return False
 
+    return is_palindrome(text[1:-1])
 
 
 # digit_match
-
+def helper(i, j):
+    if i == 0 or j == 0:
+        return 0
+    if i%10 == j%10:
+        return 1 + helper(i//10, j//10)
+    else:
+        return helper(i//10, j//10)
+
+def digit_match(i, j):
+    if i == 0 and j%10 == 0:
+        return 1
+    if i%10 == 0 and j == 0:
+        return 1
+
+    return helper(i, j)