Added unique chars challenge.

arrays_strings/unique_chars/unique_chars_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"
    ]
   },
   {
@@ -30,11 +37,13 @@
    "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",
-    "* Can I assume the string is ASCII?\n",
+    "* Can you assume the string is ASCII?\n",
     "    * Yes\n",
     "    * Note: Unicode strings could require special handling depending on your language\n",
+    "* Can we assume this is case sensitive?\n",
+    "    * Yes\n",
     "* Can you use additional data structures?  \n",
     "    * Yes"
    ]
@@ -185,15 +194,51 @@
    ]
   },
   {
-   "cell_type": "markdown",
-   "metadata": {},
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Overwriting test_unique_chars.py\n"
+     ]
+    }
+   ],
    "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.*"
+    "%%writefile test_unique_chars.py\n",
+    "from nose.tools import assert_equal\n",
+    "\n",
+    "\n",
+    "class TestUniqueChars(object):\n",
+    "\n",
+    "  def test_unique_chars(self, func):\n",
+    "        assert_equal(func(''), True)\n",
+    "        assert_equal(func('foo'), False)\n",
+    "        assert_equal(func('bar'), True)\n",
+    "        print('Success: test_unique_chars')\n",
+    "\n",
+    "def main():\n",
+    "    test = TestUniqueChars()\n",
+    "    test.test_unique_chars(unique_chars)\n",
+    "    try:\n",
+    "        test.test_unique_chars(unique_chars_hash)\n",
+    "        test.test_unique_chars(unique_chars_inplace)\n",
+    "    except NameError:\n",
+    "        # Alternate solutions are only defined\n",
+    "        # in the solutions file\n",
+    "        pass\n",
+    "    \n",
+    "if __name__ == '__main__':\n",
+    "    main()"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 5,
    "metadata": {
     "collapsed": false
    },
@@ -209,20 +254,7 @@
     }
    ],
    "source": [
-    "from nose.tools import assert_equal\n",
-    "\n",
-    "class Test(object):\n",
-    "  def test_unique_chars(self, func):\n",
-    "        assert_equal(func(''), True)\n",
-    "        assert_equal(func('foo'), False)\n",
-    "        assert_equal(func('bar'), True)\n",
-    "        print('Success: test_unique_chars')\n",
-    "\n",
-    "if __name__ == '__main__':\n",
-    "    test = Test()\n",
-    "    test.test_unique_chars(unique_chars)\n",
-    "    test.test_unique_chars(unique_chars_hash)\n",
-    "    test.test_unique_chars(unique_chars_inplace)"
+    "%run -i test_unique_chars.py"
    ]
   }
  ],