From f652c7db1e295eaaf0c24748c283f491f22992c5 Mon Sep 17 00:00:00 2001
From: Donne Martin <donne.martin@gmail.com>
Date: Tue, 5 May 2015 17:47:37 -0400
Subject: [PATCH] Added linked list find method.

---
 linked-lists/linked-list.ipynb | 75 +++++++++++++++++++++++++---------
 1 file changed, 56 insertions(+), 19 deletions(-)

diff --git a/linked-lists/linked-list.ipynb b/linked-lists/linked-list.ipynb
index 4a8ced0..ac01833 100644
--- a/linked-lists/linked-list.ipynb
+++ b/linked-lists/linked-list.ipynb
@@ -43,11 +43,14 @@
     "\n",
     "### Find\n",
     "\n",
-    "* Coming soon\n",
+    "* Find a NULL\n",
+    "* Find in an empty list\n",
+    "* Find in a list with one element or more matching elements\n",
+    "* Find in a list with no matches\n",
     "\n",
     "### Delete\n",
     "\n",
-    "* Coming soon\n",
+    "* \n",
     "\n",
     "### Print\n",
     "\n",
@@ -77,7 +80,11 @@
     "\n",
     "### Find\n",
     "\n",
-    "* Coming soon\n",
+    "* If data we are finding is NULL, return\n",
+    "* If the list is empty, return\n",
+    "* For each node\n",
+    "    * If the value is a match, return it\n",
+    "    * Else, move on to the next node\n",
     "\n",
     "Complexity:\n",
     "* Time: O(n)\n",
@@ -110,7 +117,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 19,
+   "execution_count": null,
    "metadata": {
     "collapsed": false
    },
@@ -137,6 +144,18 @@
     "        else:\n",
     "            node.next = self.head\n",
     "            self.head = node\n",
+    "            \n",
+    "    def find(self, data):\n",
+    "        if data is None:\n",
+    "            return\n",
+    "        if self.head is None:\n",
+    "            return\n",
+    "        curr_node = self.head\n",
+    "        while curr_node is not None:\n",
+    "            if curr_node.data == data:\n",
+    "                return curr_node\n",
+    "            else:\n",
+    "                curr_node = curr_node.next\n",
     "\n",
     "    def print_list(self):\n",
     "        curr_node = self.head\n",
@@ -147,23 +166,11 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 30,
+   "execution_count": null,
    "metadata": {
     "collapsed": false
    },
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "10\n",
-      "10\n",
-      "bc\n",
-      "a\n",
-      "10\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
     "# Test insert_to_front\n",
     "# Insert in an empty list\n",
@@ -181,7 +188,37 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 31,
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "# Test find\n",
+    "# Find a NULL\n",
+    "linked_list = LinkedList(None)\n",
+    "node = linked_list.find('a')\n",
+    "print(node)\n",
+    "# Find in an empty list\n",
+    "head = Node(10)\n",
+    "linked_list = LinkedList(None)\n",
+    "node = linked_list.find(None)\n",
+    "print(node)\n",
+    "# Find in a list with one element or more matching elements\n",
+    "head = Node(10)\n",
+    "linked_list = LinkedList(head)\n",
+    "linked_list.insert_to_front('a')\n",
+    "linked_list.insert_to_front('bc')\n",
+    "node = linked_list.find('a')\n",
+    "print(node)\n",
+    "# Find in a list with no matches\n",
+    "node = linked_list.find('aaa')\n",
+    "print(node)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
    "metadata": {
     "collapsed": false
    },