Added hash map challenge.

arrays_strings/hash_map/hash_map_solution.ipynb

@@ -4,7 +4,14 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "<small><i>This notebook was prepared by [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://bit.ly/code-notes).</i></small>"
+    "<small><i>This notebook was prepared by [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://github.com/donnemartin/coding-challenges).</i></small>"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Solution Notebook"
    ]
   },
   {
@@ -17,7 +24,6 @@
     "* [Test Cases](#Test-Cases)\n",
     "* [Algorithm](#Algorithm)\n",
     "* [Code](#Code)\n",
-    "* [Pythonic-Code](#Pythonic-Code)\n",
     "* [Unit Test](#Unit-Test)"
    ]
   },
@@ -27,7 +33,7 @@
    "source": [
     "## Constraints\n",
     "\n",
-    "*Problem statements are often intentionally ambiguous.  Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n",
+    "*Problem statements are sometimes ambiguous.  Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n",
     "\n",
     "* For simplicity, are the keys integers only?\n",
     "    * Yes\n",
@@ -111,11 +117,13 @@
    "outputs": [],
    "source": [
     "class Item(object):\n",
+    "    \n",
     "    def __init__(self, key, value):\n",
     "        self.key = key\n",
     "        self.value = value\n",
     "\n",
     "class HashTable(object):\n",
+    "    \n",
     "    def __init__(self, size):\n",
     "        self.size = size\n",
     "        self.table = [[] for _ in xrange(self.size)]\n",
@@ -152,13 +160,6 @@
     "## Unit Test"
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "*It is important to identify and run through general and edge cases from the [Test Cases](#Test-Cases) section by hand.  You generally will not be asked to write a unit test like what is shown below.*"
-   ]
-  },
   {
    "cell_type": "code",
    "execution_count": 2,
@@ -170,20 +171,17 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "Test: get on an empty hash table index\n",
-      "Test: set on an empty hash table index\n",
-      "Test: set on a non empty hash table index\n",
-      "Test: set on a key that already exists\n",
-      "Test: remove on a key that already exists\n",
-      "Test: remove on a key that doesn't exist\n",
-      "Success: test_end_to_end\n"
+      "Overwriting test_hash_map.py\n"
      ]
     }
    ],
    "source": [
+    "%%writefile test_hash_map.py\n",
     "from nose.tools import assert_equal\n",
     "\n",
-    "class Test(object):\n",
+    "\n",
+    "class TestHashMap(object):\n",
+    "    \n",
     "    # TODO: It would be better if we had unit tests for each\n",
     "    # method in addition to the following end-to-end test\n",
     "    def test_end_to_end(self):\n",
@@ -218,9 +216,37 @@
     "        \n",
     "        print('Success: test_end_to_end')\n",
     "\n",
+    "def main():\n",
+    "    test = TestHashMap()\n",
+    "    test.test_end_to_end()\n",
+    "    \n",
     "if __name__ == '__main__':\n",
-    "    test = Test()\n",
-    "    test.test_end_to_end()"
+    "    main()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Test: get on an empty hash table index\n",
+      "Test: set on an empty hash table index\n",
+      "Test: set on a non empty hash table index\n",
+      "Test: set on a key that already exists\n",
+      "Test: remove on a key that already exists\n",
+      "Test: remove on a key that doesn't exist\n",
+      "Success: test_end_to_end\n"
+     ]
+    }
+   ],
+   "source": [
+    "run -i test_hash_map.py"
    ]
   }
  ],