finish

part-1.py

@@ -4,17 +4,32 @@
 # the appropriate comment.
 
 # factorial
-
+def factorial(num):
+    if num < 0:
+        raise ValueError
+    if num == 0:
+        return 1
+    return num * factorial(num-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
+    return 2 + bunny(count-1)
 
 
 # is_nested_parens
-
-
+def is_nested_parens(parens):
+    if not parens:
+        return True
+    if parens[0] + parens[-1] != "()":
+        return False
+    return is_nested_parens(parens[1:-1])

part-2.py

@@ -4,13 +4,33 @@
 # the appropriate comment.
 
 # search
-
+def search(array, query):
+    if not array:
+        return False
+    elif 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 digit_match(n1, n2):
+    if n1 == 0 and n2 == 0:
+        return 1
+    def helper(a, b):
+        if a == 0 or b == 0:
+            return 0
+        if a % 10 == b % 10:
+            return 1 + helper(a // 10, b // 10)
+        else:
+            return helper(a // 10, b // 10)
+    return helper(n1, n2)