From d4d7c29c9d0147d68149f0f924815f0c923b0c5d Mon Sep 17 00:00:00 2001
From: Donne Martin <donne.martin@gmail.com>
Date: Sun, 5 Jul 2015 08:54:49 -0400
Subject: [PATCH] Tweaked compress challenge.

---
 .../compress/compress_solution.ipynb          | 29 ++++++++++---------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/arrays_strings/compress/compress_solution.ipynb b/arrays_strings/compress/compress_solution.ipynb
index 0444448..1b80285 100644
--- a/arrays_strings/compress/compress_solution.ipynb
+++ b/arrays_strings/compress/compress_solution.ipynb
@@ -66,9 +66,10 @@
    "source": [
     "## Algorithm: List\n",
     "\n",
-    "Since Python strings are immutable, we'll use a list of characters instead to exercise string manipulation as you would get with a C string.  We'll convert the list to a string at the end of the algorithm.\n",
+    "Since Python strings are immutable, we'll use a list of characters to build the compressed string representation.  We'll then convert the list to a string.\n",
     "\n",
     "* Calculate the size of the compressed string\n",
+    "    * Note the constraint about compressing only if it saves space\n",
     "* If the compressed string size is >= string size, return string\n",
     "* Create compressed_string\n",
     "    * For each char in string\n",
@@ -84,7 +85,7 @@
     "\n",
     "Complexity:\n",
     "* Time: O(n)\n",
-    "* Space: O(n) additional space for the list"
+    "* Space: O(n)"
    ]
   },
   {
@@ -134,6 +135,8 @@
     "            last_char = char\n",
     "    compressed_string.append(last_char)\n",
     "    compressed_string.append(str(count))\n",
+    "    \n",
+    "    # Convert the characters in the list to a string\n",
     "    return \"\".join(compressed_string)"
    ]
   },
@@ -143,13 +146,20 @@
    "source": [
     "## Algorithm: Byte Array\n",
     "\n",
-    "As a bonus solution, we can solve this problem with a byte array.\n",
+    "As a bonus solution, we can also solve this problem with a byte array.\n",
     "\n",
-    "The byte array algorithm similar when using a list, except we will need to work with the bytearray's character codes (using the function ord) instead of the characters as we did above when we implemented this solution with a list.\n",
+    "The byte array algorithm similar when using a list, except we will need to work with the bytearray's character codes (using the function ord) instead of the characters as when we implemented this solution with a list.\n",
     "\n",
     "Complexity:\n",
     "* Time: O(n)\n",
-    "* Space: O(m) where m is the size of the compressed bytearray"
+    "* Space: O(n)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Code: Byte Array"
    ]
   },
   {
@@ -194,14 +204,7 @@
     "            last_char_code = char_code\n",
     "    compressed_string[pos] = last_char_code\n",
     "    compressed_string[pos+1] = ord(str(count))\n",
-    "    return compressed_string"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "## Code: Byte Array"
+    "    return str(compressed_string)"
    ]
   },
   {