Added notebook solving the following: Implement insertion sort.

README.md

@@ -46,6 +46,7 @@ Most solutions are in Python.
 ## Sorting and Searching
 
 * [Implement selection sort](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/sorting-searching/selection-sort.ipynb#)
+* [Implement insertion sort](http://nbviewer.ipython.org/github/donnemartin/algorithms-data-structures/blob/master/sorting-searching/insertion-sort.ipynb#)
 
 ## Hacker Rank
 

sorting-searching/insertion-sort.ipynb

@@ -0,0 +1,124 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Problem: Implement insertion sort.\n",
+    "\n",
+    "* [Clarifying Questions](#Clarifying-Questions)\n",
+    "* [Test Cases](#Test-Cases)\n",
+    "* [Algorithm](#Algorithm)\n",
+    "* [Code](#Code)\n",
+    "* [Pythonic-Code](#Pythonic-Code)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Clarifying Questions\n",
+    "\n",
+    "* Are we sorting integers?\n",
+    "    * Yes\n",
+    "* Can we assume the input is valid integers?\n",
+    "    * Yes\n",
+    "* Can we have duplicate integers?\n",
+    "    * Yes"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Test Cases\n",
+    "\n",
+    "* Empty input\n",
+    "* One element\n",
+    "* Two or more elements"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Algorithm\n",
+    "\n",
+    "Wikipedia's animation:\n",
+    "![alt text](http://upload.wikimedia.org/wikipedia/commons/0/0f/Insertion-sort-example-300px.gif)\n",
+    "\n",
+    "* For each value index 1 to n - 1\n",
+    "    * Compare with all elements to the left of the current value to determine new insertion point\n",
+    "        * Hold current value in temp variable\n",
+    "        * Shift elements from new insertion point right\n",
+    "        * Insert value in temp variable\n",
+    "        * Break\n",
+    "\n",
+    "Complexity:\n",
+    "* Time: O(n^2) avarage, worst.  O(1) best if input is already sorted.\n",
+    "* Space: O(1)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Code"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "def insertion_sort(data):\n",
+    "    if len(data) < 2:\n",
+    "        return\n",
+    "    for r in xrange(1, len(data)):\n",
+    "        for l in xrange(0, r):\n",
+    "            if data[l] > data[r]:\n",
+    "                temp = data[r]\n",
+    "                data[l+1:r+1] = data[l:r]\n",
+    "                data[l] = temp\n",
+    "                break\n",
+    "\n",
+    "print('Empty input')\n",
+    "data = []\n",
+    "insertion_sort(data)\n",
+    "print(data)\n",
+    "print('One element')\n",
+    "data = [5]\n",
+    "insertion_sort(data)\n",
+    "print(data)\n",
+    "print('Two or more elements')\n",
+    "data = [5, 1, 7, 2, 6, -3, 5, 7, -1]\n",
+    "insertion_sort(data)\n",
+    "print(data)"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.9"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}