From 4e003730ee9aea85bd409bc93e1611898f71a625 Mon Sep 17 00:00:00 2001
From: Diana <dianah46@gmail.com>
Date: Fri, 15 Nov 2019 17:23:03 -0800
Subject: [PATCH 1/2] will skip nested(s) function for now

---
 lib/recursive-methods.rb       | 34 +++++++++++++++++++++-------------
 test/recursion_writing_test.rb |  6 +++---
 2 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/lib/recursive-methods.rb b/lib/recursive-methods.rb
index fbf6faa..3a487dd 100644
--- a/lib/recursive-methods.rb
+++ b/lib/recursive-methods.rb
@@ -1,33 +1,41 @@
 # Authoring recursive algorithms. Add comments including time and space complexity for each method.
 
-# Time complexity: ?
-# Space complexity: ?
+# Time complexity: O(n)
+# Space complexity: O(n)
 def factorial(n)
-    raise NotImplementedError, "Method not implemented"
+  if n < 0
+    raise ArgumentError
+  end
+  return 1 if n == 0
+  return n * factorial(n-1)
 end
 
-# Time complexity: ?
-# Space complexity: ?
+# Time complexity: O(n)
+# Space complexity: O(n)
+# I think this is reversing the string in place?
 def reverse(s)
-    raise NotImplementedError, "Method not implemented"
+  return s if s.length <= 1
+  return reverse(s[1..-1]) + s[0]
 end
 
-# Time complexity: ?
-# Space complexity: ?
+# Time complexity: O(n)
+# Space complexity: O(n)
 def reverse_inplace(s)
-    raise NotImplementedError, "Method not implemented"
+  return s if s.length <= 1
+  return reverse_inplace(s[1..-1]) + s[0]
 end
 
-# Time complexity: ?
-# Space complexity: ?
+# Time complexity: O(n)
+# Space complexity: O(n)
 def bunny(n)
-    raise NotImplementedError, "Method not implemented"
+  return n if n == 0
+  return 2 + bunny(n-1)
 end
 
 # Time complexity: ?
 # Space complexity: ?
 def nested(s)
-    raise NotImplementedError, "Method not implemented"
+  return true if s.length == 0
 end
 
 # Time complexity: ?
diff --git a/test/recursion_writing_test.rb b/test/recursion_writing_test.rb
index 820810e..36e73c4 100644
--- a/test/recursion_writing_test.rb
+++ b/test/recursion_writing_test.rb
@@ -38,7 +38,7 @@
   end
 end
 
-xdescribe "reverse" do
+describe "reverse" do
   it "will reverse 'cat'" do
     # Arrange
     string = "cat"
@@ -84,7 +84,7 @@
 end
 
 
-xdescribe "reverse_in_place" do
+describe "reverse_in_place" do
   it "will reverse 'cat'" do
     # Arrange
     string = "cat"
@@ -129,7 +129,7 @@
   end
 end
 
-xdescribe "bunny" do
+describe "bunny" do
   it "returns 0 for 0 bunnies" do
     # Arrange
     count = 0

From 6d404547a295068e0fe1a73e1f6b6a60a65c432e Mon Sep 17 00:00:00 2001
From: Diana <dianah46@gmail.com>
Date: Fri, 15 Nov 2019 18:52:01 -0800
Subject: [PATCH 2/2] need some help with nested and digit_match

---
 lib/recursive-methods.rb | 50 +++++++++++++++++++++++++++++++---------
 1 file changed, 39 insertions(+), 11 deletions(-)

diff --git a/lib/recursive-methods.rb b/lib/recursive-methods.rb
index 3a487dd..9071afc 100644
--- a/lib/recursive-methods.rb
+++ b/lib/recursive-methods.rb
@@ -1,5 +1,5 @@
 # Authoring recursive algorithms. Add comments including time and space complexity for each method.
-
+require 'pry'
 # Time complexity: O(n)
 # Space complexity: O(n)
 def factorial(n)
@@ -34,24 +34,52 @@ def bunny(n)
 
 # Time complexity: ?
 # Space complexity: ?
+# NOT PASSING TESTS
 def nested(s)
   return true if s.length == 0
+  # need to check if s = even number of paren-pairs()
+  # return true if s.length % 2 == 0
 end
 
-# Time complexity: ?
-# Space complexity: ?
-def search(array, value)
-    raise NotImplementedError, "Method not implemented"
+# Time complexity: O(n)
+# Space complexity: O(n)
+def search(array, value, i = 0)
+  return false if i >= array.length
+  return true if array[i] == value
+  return search(array, value, i + 1)
 end
 
-# Time complexity: ?
-# Space complexity: ?
-def is_palindrome(s)
-    raise NotImplementedError, "Method not implemented"
+# Time complexity: O(n)
+# Space complexity: O(n)
+# ONLY PASSING 2 TESTS
+def is_palindrome(s, l = 0, r = s.length-1 )
+  if s[l] == s[r]
+    return true
+  else
+    return false
+  end
+
+  while l < s.length
+    return is_palindrome(s, l + 1, r - 1)
+  end
 end
 
 # Time complexity: ?
 # Space complexity: ?
-def digit_match(n, m)
-    raise NotImplementedError, "Method not implemented"
+# NOT PASSING TESTS
+def digit_match(n, m, i = -1)
+# i want to check each index from the end and keep track of matching values
+  n = n.to_s
+  m = m.to_s
+  tracker = 0
+
+  if n[i] == m[i]
+    tracker += 1
+  else
+    tracker += 0
+  end
+
+  return tracker if i < -(n.length)
+
+  return digit_match(n, m, i - 1)
 end
\ No newline at end of file