diff --git a/stacks_queues/hanoi/__init__.py b/stacks_queues/hanoi/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/stacks_queues/hanoi/hanoi_challenge.ipynb b/stacks_queues/hanoi/hanoi_challenge.ipynb
new file mode 100644
index 0000000..dcec850
--- /dev/null
+++ b/stacks_queues/hanoi/hanoi_challenge.ipynb
@@ -0,0 +1,187 @@
+{
+ "cells": [
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "This notebook was prepared by [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://github.com/donnemartin/coding-challenges)."
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "# Challenge Notebook"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Problem: Implement the [Towers of Hanoi](http://en.wikipedia.org/wiki/Tower_of_Hanoi) with 3 towers and N disks.\n",
+ "\n",
+ "* [Constraints](#Constraints)\n",
+ "* [Test Cases](#Test-Cases)\n",
+ "* [Algorithm](#Algorithm)\n",
+ "* [Code](#Code)\n",
+ "* [Unit Test](#Unit-Test)\n",
+ "* [Solution Notebook](#Solution-Notebook)"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Constraints\n",
+ "\n",
+ "*Problem statements are sometimes ambiguous. Identifying constraints and stating assumptions can help to ensure you code the intended solution.*\n",
+ "\n",
+ "* Can we assume we already have a stack class that can be used for this problem?\n",
+ " * Yes"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Test Cases\n",
+ "\n",
+ "* NULL tower(s)\n",
+ "* 0 disks\n",
+ "* 1 disk\n",
+ "* 2 or more disks"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Algorithm\n",
+ "\n",
+ "Refer to the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/coding-challenges/blob/master/stacks_queues/hanoi/hanoi_solution.ipynb). If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start."
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Code"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": null,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [],
+ "source": [
+ "%run ../stack/stack.py\n",
+ "%load ../stack/stack.py"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": null,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [],
+ "source": [
+ "def hanoi(num_disks, src, dest, buff):\n",
+ " # TODO: Implement me\n",
+ " pass"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Unit Test\n",
+ "\n",
+ "\n",
+ "\n",
+ "**The following unit test is expected to fail until you solve the challenge.**"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": null,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [],
+ "source": [
+ "# %load test_hanoi.py\n",
+ "from nose.tools import assert_equal\n",
+ "\n",
+ "\n",
+ "class TestHanoi(object):\n",
+ " \n",
+ " def test_hanoi(self):\n",
+ " num_disks = 3\n",
+ " src = Stack()\n",
+ " buff = Stack()\n",
+ " dest = Stack()\n",
+ "\n",
+ " print('Test: NULL towers')\n",
+ " hanoi(num_disks, None, None, None)\n",
+ "\n",
+ " print('Test: 0 disks')\n",
+ " hanoi(num_disks, src, dest, buff)\n",
+ " assert_equal(dest.pop(), None)\n",
+ "\n",
+ " print('Test: 1 disk')\n",
+ " src.push(5)\n",
+ " hanoi(num_disks, src, dest, buff)\n",
+ " assert_equal(dest.pop(), 5)\n",
+ "\n",
+ " print('Test: 2 or more disks')\n",
+ " for i in xrange(num_disks, -1, -1):\n",
+ " src.push(i)\n",
+ " hanoi(num_disks, src, dest, buff)\n",
+ " for i in xrange(0, num_disks):\n",
+ " assert_equal(dest.pop(), i)\n",
+ "\n",
+ " print('Success: test_hanoi')\n",
+ "\n",
+ "def main():\n",
+ " test = TestHanoi()\n",
+ " test.test_hanoi()\n",
+ " \n",
+ "if __name__ == '__main__':\n",
+ " main()"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Solution Notebook\n",
+ "\n",
+ "Review the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/coding-challenges/blob/master/stacks_queues/hanoi/hanoi_solution.ipynb) for a discussion on algorithms and code solutions."
+ ]
+ }
+ ],
+ "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": "2.7.10"
+ }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/stacks_queues/hanoi/hanoi_solution.ipynb b/stacks_queues/hanoi/hanoi_solution.ipynb
index 68ada38..b419ccd 100644
--- a/stacks_queues/hanoi/hanoi_solution.ipynb
+++ b/stacks_queues/hanoi/hanoi_solution.ipynb
@@ -4,7 +4,14 @@
"cell_type": "markdown",
"metadata": {},
"source": [
- "This notebook was prepared by [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://bit.ly/code-notes)."
+ "This notebook was prepared by [Donne Martin](http://donnemartin.com). Source and license info is on [GitHub](https://github.com/donnemartin/coding-challenges)."
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "# Solution Notebook"
]
},
{
@@ -26,7 +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",
"* Can we assume we already have a stack class that can be used for this problem?\n",
" * Yes"
@@ -38,7 +45,7 @@
"source": [
"## Test Cases\n",
"\n",
- "* NULL towers\n",
+ "* NULL tower(s)\n",
"* 0 disks\n",
"* 1 disk\n",
"* 2 or more disks"
@@ -73,11 +80,11 @@
"cell_type": "code",
"execution_count": 1,
"metadata": {
- "collapsed": true
+ "collapsed": false
},
"outputs": [],
"source": [
- "%run stack.py"
+ "%run ../stack/stack.py"
]
},
{
@@ -103,8 +110,7 @@
"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.*"
+ "\n"
]
},
{
@@ -118,18 +124,17 @@
"name": "stdout",
"output_type": "stream",
"text": [
- "Test: NULL towers\n",
- "Test: 0 disks\n",
- "Test: 1 disk\n",
- "Test: 2 or more disks\n",
- "Success: test_hanoi\n"
+ "Overwriting test_hanoi.py\n"
]
}
],
"source": [
+ "%%writefile test_hanoi.py\n",
"from nose.tools import assert_equal\n",
"\n",
- "class Test(object):\n",
+ "\n",
+ "class TestHanoi(object):\n",
+ " \n",
" def test_hanoi(self):\n",
" num_disks = 3\n",
" src = Stack()\n",
@@ -157,9 +162,35 @@
"\n",
" print('Success: test_hanoi')\n",
"\n",
+ "def main():\n",
+ " test = TestHanoi()\n",
+ " test.test_hanoi()\n",
+ " \n",
"if __name__ == '__main__':\n",
- " test = Test()\n",
- " test.test_hanoi()"
+ " main()"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 4,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "Test: NULL towers\n",
+ "Test: 0 disks\n",
+ "Test: 1 disk\n",
+ "Test: 2 or more disks\n",
+ "Success: test_hanoi\n"
+ ]
+ }
+ ],
+ "source": [
+ "%run -i test_hanoi.py"
]
}
],
diff --git a/stacks_queues/hanoi/test_hanoi.py b/stacks_queues/hanoi/test_hanoi.py
new file mode 100644
index 0000000..9e230a6
--- /dev/null
+++ b/stacks_queues/hanoi/test_hanoi.py
@@ -0,0 +1,38 @@
+from nose.tools import assert_equal
+
+
+class TestHanoi(object):
+
+ def test_hanoi(self):
+ num_disks = 3
+ src = Stack()
+ buff = Stack()
+ dest = Stack()
+
+ print('Test: NULL towers')
+ hanoi(num_disks, None, None, None)
+
+ print('Test: 0 disks')
+ hanoi(num_disks, src, dest, buff)
+ assert_equal(dest.pop(), None)
+
+ print('Test: 1 disk')
+ src.push(5)
+ hanoi(num_disks, src, dest, buff)
+ assert_equal(dest.pop(), 5)
+
+ print('Test: 2 or more disks')
+ for i in xrange(num_disks, -1, -1):
+ src.push(i)
+ hanoi(num_disks, src, dest, buff)
+ for i in xrange(0, num_disks):
+ assert_equal(dest.pop(), i)
+
+ print('Success: test_hanoi')
+
+def main():
+ test = TestHanoi()
+ test.test_hanoi()
+
+if __name__ == '__main__':
+ main()
\ No newline at end of file