Reworked notebook: Added more detail to constraints and test cases. Reworked code and unit test.

recursion-dynamic/fibonacci.ipynb

@@ -13,18 +13,22 @@
    "source": [
     "## Problem: Implement fibonacci recursively, dynamically, and iteratively.\n",
     "\n",
-    "* [Clarifying Questions](#Clarifying-Questions)\n",
+    "* [Constraints and Assumptions](#Constraints-and-Assumptions)\n",
     "* [Test Cases](#Test-Cases)\n",
     "* [Algorithm](#Algorithm)\n",
-    "* [Code](#Code)\n",
-    "* [Pythonic-Code](#Pythonic-Code)"
+    "* [Code: Recursive](#Code:-Recursive)\n",
+    "* [Code: Dynamic](#Code:-Dynamic)\n",
+    "* [Code: Iterative](#Code:-Iterative)\n",
+    "* [Unit Test](#Unit-Test)"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Clarifying Questions\n",
+    "## Constraints and Assumptions\n",
+    "\n",
+    "*Problem statements are often intentionally ambiguous.  Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n",
     "\n",
     "* None"
    ]
@@ -59,23 +63,12 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Code"
+    "## Code: Recursive"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": [
-    "num_items = 10"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 1,
    "metadata": {
     "collapsed": false
    },
@@ -85,20 +78,25 @@
     "    if n == 0 or n == 1:\n",
     "        return n\n",
     "    else:\n",
-    "        return fib_recursive(n-1) + fib_recursive(n-2)\n",
-    "\n",
-    "for i in xrange(num_items):\n",
-    "    print(fib_recursive(i))"
+    "        return fib_recursive(n-1) + fib_recursive(n-2)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Code: Dynamic"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 2,
    "metadata": {
     "collapsed": false
    },
    "outputs": [],
    "source": [
+    "num_items = 10\n",
     "cache = [None] * (num_items + 1)\n",
     "\n",
     "def fib_dynamic(n):\n",
@@ -107,15 +105,19 @@
     "    if cache[n] != None:\n",
     "        return cache[n]\n",
     "    cache[n] = fib_dynamic(n-1) + fib_dynamic(n-2)\n",
-    "    return cache[n]\n",
-    "\n",
-    "for i in xrange(num_items):\n",
-    "    print(fib_dynamic(i))"
+    "    return cache[n]"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Code: Iterative"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 3,
    "metadata": {
     "collapsed": false
    },
@@ -126,10 +128,52 @@
     "    b = 1\n",
     "    for _ in xrange(n):\n",
     "        a, b = b, a + b\n",
-    "        return a\n",
+    "    return a"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Unit Test\n",
     "\n",
+    "*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": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Success: test_fib\n",
+      "Success: test_fib\n",
+      "Success: test_fib\n"
+     ]
+    }
+   ],
+   "source": [
+    "from nose.tools import assert_equal\n",
+    "\n",
+    "class Test(object):\n",
+    "    def test_fib(self, func):\n",
+    "        result = []\n",
     "        for i in xrange(num_items):\n",
-    "    print(fib_iterative(i))"
+    "            result.append(func(i))\n",
+    "        fib_seq = [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]\n",
+    "        assert_equal(result, fib_seq)\n",
+    "        print('Success: test_fib')\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    test = Test()\n",
+    "    test.test_fib(fib_recursive)\n",
+    "    test.test_fib(fib_dynamic)\n",
+    "    test.test_fib(fib_iterative)"
    ]
   }
  ],