diff --git a/linked_lists/linked_list/linked_list.py b/linked_lists/linked_list/linked_list.py
index f6406a8..d888321 100644
--- a/linked_lists/linked_list/linked_list.py
+++ b/linked_lists/linked_list/linked_list.py
@@ -1,5 +1,5 @@
-
class Node(object):
+
def __init__(self, data, next_node=None):
self.next = next_node
self.data = data
@@ -8,6 +8,7 @@ class Node(object):
return self.data
class LinkedList(object):
+
def __init__(self, head=None):
self.head = head
diff --git a/linked_lists/linked_list/linked_list_challenge.ipynb b/linked_lists/linked_list/linked_list_challenge.ipynb
new file mode 100644
index 0000000..ed0549d
--- /dev/null
+++ b/linked_lists/linked_list/linked_list_challenge.ipynb
@@ -0,0 +1,331 @@
+{
+ "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 a linked list with insert, append, find, delete, length, and print methods\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",
+ "* Is this a singly or doubly linked list?\n",
+ " * Singly\n",
+ "* Is this a circular list?\n",
+ " * No\n",
+ "* Do we keep track of the tail or just the head?\n",
+ " * Just the head"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Test Cases\n",
+ "\n",
+ "### Insert to Front\n",
+ "\n",
+ "* Insert a NULL\n",
+ "* Insert in an empty list\n",
+ "* Insert in a list with one element or more elements\n",
+ "\n",
+ "### Append\n",
+ "\n",
+ "* Append a NULL\n",
+ "* Append in an empty list\n",
+ "* Insert in a list with one element or more elements\n",
+ "\n",
+ "### Find\n",
+ "\n",
+ "* Find a NULL\n",
+ "* Find in an empty list\n",
+ "* Find in a list with one element or more matching elements\n",
+ "* Find in a list with no matches\n",
+ "\n",
+ "### Delete\n",
+ "\n",
+ "* Delete a NULL\n",
+ "* Delete in an empty list\n",
+ "* Delete in a list with one element or more matching elements\n",
+ "* Delete in a list with no matches\n",
+ "\n",
+ "### Length\n",
+ "\n",
+ "* Length of zero or more elements\n",
+ "\n",
+ "### Print\n",
+ "\n",
+ "* Print an empty list\n",
+ "* Print a list with one or more elements"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Algorithm\n",
+ "\n",
+ "Refer to the [Solution Notebook](http://nbviewer.ipython.org/github/donnemartin/coding-challenges/blob/master/linked_lists/linked_list/linked_list_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": [
+ "class Node(object):\n",
+ " \n",
+ " def __init__(self, data, next_node=None):\n",
+ " pass\n",
+ " # TODO: Implement me\n",
+ " \n",
+ " def __str__(self):\n",
+ " pass\n",
+ " # TODO: Implement me\n",
+ "\n",
+ "class LinkedList(object):\n",
+ " \n",
+ " def __init__(self, head=None):\n",
+ " pass\n",
+ " # TODO: Implement me\n",
+ "\n",
+ " def __len__(self):\n",
+ " pass\n",
+ " # TODO: Implement me\n",
+ " \n",
+ " def insert_to_front(self, data):\n",
+ " pass\n",
+ " # TODO: Implement me\n",
+ " \n",
+ " def append(self, data, next_node=None):\n",
+ " pass\n",
+ " # TODO: Implement me\n",
+ " \n",
+ " def find(self, data):\n",
+ " pass\n",
+ " # TODO: Implement me\n",
+ " \n",
+ " def delete(self, data):\n",
+ " pass\n",
+ " # TODO: Implement me\n",
+ "\n",
+ " def print_list(self):\n",
+ " pass\n",
+ " # TODO: Implement me\n",
+ "\n",
+ " def get_all_data(self):\n",
+ " pass\n",
+ " # TODO: Implement me"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Unit Test"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "\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_linked_list.py\n",
+ "from nose.tools import assert_equal\n",
+ "\n",
+ "\n",
+ "class TestLinkedList(object):\n",
+ " \n",
+ " def test_insert_to_front(self):\n",
+ " print('Test: insert_to_front on an empty list')\n",
+ " linked_list = LinkedList(None)\n",
+ " linked_list.insert_to_front(10)\n",
+ " assert_equal(linked_list.get_all_data(), [10])\n",
+ "\n",
+ " print('Test: insert_to_front on a NULL')\n",
+ " linked_list.insert_to_front(None)\n",
+ " assert_equal(linked_list.get_all_data(), [10])\n",
+ "\n",
+ " print('Test: insert_to_front general case')\n",
+ " linked_list.insert_to_front('a')\n",
+ " linked_list.insert_to_front('bc')\n",
+ " assert_equal(linked_list.get_all_data(), ['bc', 'a', 10])\n",
+ " \n",
+ " print('Success: test_insert_to_front\\n')\n",
+ " \n",
+ " def test_append(self):\n",
+ " print('Test: append on an empty list')\n",
+ " linked_list = LinkedList(None)\n",
+ " linked_list.append(10)\n",
+ " assert_equal(linked_list.get_all_data(), [10])\n",
+ "\n",
+ " print('Test: append a NULL')\n",
+ " linked_list.append(None)\n",
+ " assert_equal(linked_list.get_all_data(), [10])\n",
+ "\n",
+ " print('Test: append general case')\n",
+ " linked_list.append('a')\n",
+ " linked_list.append('bc')\n",
+ " assert_equal(linked_list.get_all_data(), [10, 'a', 'bc'])\n",
+ " \n",
+ " print('Success: test_append\\n')\n",
+ " \n",
+ " def test_find(self):\n",
+ " print('Test: find on an empty list')\n",
+ " linked_list = LinkedList(None)\n",
+ " node = linked_list.find('a')\n",
+ " assert_equal(node, None)\n",
+ "\n",
+ " print('Test: find a NULL')\n",
+ " head = Node(10)\n",
+ " linked_list = LinkedList(head)\n",
+ " node = linked_list.find(None)\n",
+ " assert_equal(node, None)\n",
+ "\n",
+ " print('Test: find general case with matches')\n",
+ " head = Node(10)\n",
+ " linked_list = LinkedList(head)\n",
+ " linked_list.insert_to_front('a')\n",
+ " linked_list.insert_to_front('bc')\n",
+ " node = linked_list.find('a')\n",
+ " assert_equal(str(node), 'a')\n",
+ "\n",
+ " print('Test: find general case with no matches')\n",
+ " node = linked_list.find('aaa')\n",
+ " assert_equal(node, None)\n",
+ " \n",
+ " print('Success: test_find\\n')\n",
+ " \n",
+ " def test_delete(self):\n",
+ " print('Test: delete on an empty list')\n",
+ " linked_list = LinkedList(None)\n",
+ " linked_list.delete('a')\n",
+ " assert_equal(linked_list.get_all_data(), [])\n",
+ "\n",
+ " print('Test: delete a NULL')\n",
+ " head = Node(10)\n",
+ " linked_list = LinkedList(head)\n",
+ " linked_list.delete(None)\n",
+ " assert_equal(linked_list.get_all_data(), [10])\n",
+ "\n",
+ " print('Test: delete general case with matches')\n",
+ " head = Node(10)\n",
+ " linked_list = LinkedList(head)\n",
+ " linked_list.insert_to_front('a')\n",
+ " linked_list.insert_to_front('bc')\n",
+ " linked_list.delete('a')\n",
+ " assert_equal(linked_list.get_all_data(), ['bc', 10])\n",
+ "\n",
+ " print('Test: delete general case with no matches')\n",
+ " linked_list.delete('aa')\n",
+ " assert_equal(linked_list.get_all_data(), ['bc', 10])\n",
+ " \n",
+ " print('Success: test_delete\\n')\n",
+ " \n",
+ " def test_len(self):\n",
+ " print('Test: len on an empty list')\n",
+ " linked_list = LinkedList(None)\n",
+ " assert_equal(len(linked_list), 0)\n",
+ "\n",
+ " print('Test: len general case')\n",
+ " head = Node(10)\n",
+ " linked_list = LinkedList(head)\n",
+ " linked_list.insert_to_front('a')\n",
+ " linked_list.insert_to_front('bc')\n",
+ " assert_equal(len(linked_list), 3)\n",
+ " \n",
+ " print('Success: test_len\\n')\n",
+ "\n",
+ "def main():\n",
+ " test = TestLinkedList()\n",
+ " test.test_insert_to_front()\n",
+ " test.test_append()\n",
+ " test.test_find()\n",
+ " test.test_delete()\n",
+ " test.test_len()\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/linked_lists/linked_list/linked_list_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/linked_lists/linked_list/linked_list_solution.ipynb b/linked_lists/linked_list/linked_list_solution.ipynb
index 2255f0e..58cae19 100644
--- a/linked_lists/linked_list/linked_list_solution.ipynb
+++ b/linked_lists/linked_list/linked_list_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",
"* Is this a singly or doubly linked list?\n",
" * Singly\n",
@@ -181,8 +188,8 @@
],
"source": [
"%%writefile linked_list.py\n",
- "\n",
"class Node(object):\n",
+ " \n",
" def __init__(self, data, next_node=None):\n",
" self.next = next_node\n",
" self.data = data\n",
@@ -191,6 +198,7 @@
" return self.data\n",
"\n",
"class LinkedList(object):\n",
+ " \n",
" def __init__(self, head=None):\n",
" self.head = head\n",
"\n",
@@ -287,13 +295,6 @@
"## 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": 3,
@@ -305,39 +306,17 @@
"name": "stdout",
"output_type": "stream",
"text": [
- "Test: insert_to_front on an empty list\n",
- "Test: insert_to_front on a NULL\n",
- "Test: insert_to_front general case\n",
- "Success: test_insert_to_front\n",
- "\n",
- "Test: append on an empty list\n",
- "Test: append a NULL\n",
- "Test: append general case\n",
- "Success: test_append\n",
- "\n",
- "Test: find on an empty list\n",
- "Test: find a NULL\n",
- "Test: find general case with matches\n",
- "Test: find general case with no matches\n",
- "Success: test_find\n",
- "\n",
- "Test: delete on an empty list\n",
- "Test: delete a NULL\n",
- "Test: delete general case with matches\n",
- "Test: delete general case with no matches\n",
- "Success: test_delete\n",
- "\n",
- "Test: len on an empty list\n",
- "Test: len general case\n",
- "Success: test_len\n",
- "\n"
+ "Overwriting test_linked_list.py\n"
]
}
],
"source": [
+ "%%writefile test_linked_list.py\n",
"from nose.tools import assert_equal\n",
"\n",
- "class Test(object):\n",
+ "\n",
+ "class TestLinkedList(object):\n",
+ " \n",
" def test_insert_to_front(self):\n",
" print('Test: insert_to_front on an empty list')\n",
" linked_list = LinkedList(None)\n",
@@ -438,13 +417,60 @@
" \n",
" print('Success: test_len\\n')\n",
"\n",
- "if __name__ == '__main__':\n",
- " test = Test()\n",
+ "def main():\n",
+ " test = TestLinkedList()\n",
" test.test_insert_to_front()\n",
" test.test_append()\n",
" test.test_find()\n",
" test.test_delete()\n",
- " test.test_len()"
+ " test.test_len()\n",
+ " \n",
+ "if __name__ == '__main__':\n",
+ " main()"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 4,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "Test: insert_to_front on an empty list\n",
+ "Test: insert_to_front on a NULL\n",
+ "Test: insert_to_front general case\n",
+ "Success: test_insert_to_front\n",
+ "\n",
+ "Test: append on an empty list\n",
+ "Test: append a NULL\n",
+ "Test: append general case\n",
+ "Success: test_append\n",
+ "\n",
+ "Test: find on an empty list\n",
+ "Test: find a NULL\n",
+ "Test: find general case with matches\n",
+ "Test: find general case with no matches\n",
+ "Success: test_find\n",
+ "\n",
+ "Test: delete on an empty list\n",
+ "Test: delete a NULL\n",
+ "Test: delete general case with matches\n",
+ "Test: delete general case with no matches\n",
+ "Success: test_delete\n",
+ "\n",
+ "Test: len on an empty list\n",
+ "Test: len general case\n",
+ "Success: test_len\n",
+ "\n"
+ ]
+ }
+ ],
+ "source": [
+ "%run -i test_linked_list.py"
]
}
],
diff --git a/linked_lists/linked_list/test_linked_list.py b/linked_lists/linked_list/test_linked_list.py
new file mode 100644
index 0000000..5899f35
--- /dev/null
+++ b/linked_lists/linked_list/test_linked_list.py
@@ -0,0 +1,115 @@
+from nose.tools import assert_equal
+
+
+class TestLinkedList(object):
+
+ def test_insert_to_front(self):
+ print('Test: insert_to_front on an empty list')
+ linked_list = LinkedList(None)
+ linked_list.insert_to_front(10)
+ assert_equal(linked_list.get_all_data(), [10])
+
+ print('Test: insert_to_front on a NULL')
+ linked_list.insert_to_front(None)
+ assert_equal(linked_list.get_all_data(), [10])
+
+ print('Test: insert_to_front general case')
+ linked_list.insert_to_front('a')
+ linked_list.insert_to_front('bc')
+ assert_equal(linked_list.get_all_data(), ['bc', 'a', 10])
+
+ print('Success: test_insert_to_front\n')
+
+ def test_append(self):
+ print('Test: append on an empty list')
+ linked_list = LinkedList(None)
+ linked_list.append(10)
+ assert_equal(linked_list.get_all_data(), [10])
+
+ print('Test: append a NULL')
+ linked_list.append(None)
+ assert_equal(linked_list.get_all_data(), [10])
+
+ print('Test: append general case')
+ linked_list.append('a')
+ linked_list.append('bc')
+ assert_equal(linked_list.get_all_data(), [10, 'a', 'bc'])
+
+ print('Success: test_append\n')
+
+ def test_find(self):
+ print('Test: find on an empty list')
+ linked_list = LinkedList(None)
+ node = linked_list.find('a')
+ assert_equal(node, None)
+
+ print('Test: find a NULL')
+ head = Node(10)
+ linked_list = LinkedList(head)
+ node = linked_list.find(None)
+ assert_equal(node, None)
+
+ print('Test: find general case with matches')
+ head = Node(10)
+ linked_list = LinkedList(head)
+ linked_list.insert_to_front('a')
+ linked_list.insert_to_front('bc')
+ node = linked_list.find('a')
+ assert_equal(str(node), 'a')
+
+ print('Test: find general case with no matches')
+ node = linked_list.find('aaa')
+ assert_equal(node, None)
+
+ print('Success: test_find\n')
+
+ def test_delete(self):
+ print('Test: delete on an empty list')
+ linked_list = LinkedList(None)
+ linked_list.delete('a')
+ assert_equal(linked_list.get_all_data(), [])
+
+ print('Test: delete a NULL')
+ head = Node(10)
+ linked_list = LinkedList(head)
+ linked_list.delete(None)
+ assert_equal(linked_list.get_all_data(), [10])
+
+ print('Test: delete general case with matches')
+ head = Node(10)
+ linked_list = LinkedList(head)
+ linked_list.insert_to_front('a')
+ linked_list.insert_to_front('bc')
+ linked_list.delete('a')
+ assert_equal(linked_list.get_all_data(), ['bc', 10])
+
+ print('Test: delete general case with no matches')
+ linked_list.delete('aa')
+ assert_equal(linked_list.get_all_data(), ['bc', 10])
+
+ print('Success: test_delete\n')
+
+ def test_len(self):
+ print('Test: len on an empty list')
+ linked_list = LinkedList(None)
+ assert_equal(len(linked_list), 0)
+
+ print('Test: len general case')
+ head = Node(10)
+ linked_list = LinkedList(head)
+ linked_list.insert_to_front('a')
+ linked_list.insert_to_front('bc')
+ assert_equal(len(linked_list), 3)
+
+ print('Success: test_len\n')
+
+def main():
+ test = TestLinkedList()
+ test.test_insert_to_front()
+ test.test_append()
+ test.test_find()
+ test.test_delete()
+ test.test_len()
+
+if __name__ == '__main__':
+ main()
\ No newline at end of file