Added basic graph implementation challenge.

This commit is contained in:
Donne Martin 2015-08-03 06:24:38 -04:00
parent 9d1a68fb40
commit 92e0318952
6 changed files with 543 additions and 0 deletions

View File

@ -207,6 +207,7 @@ Challenges, solutions, and unit tests are presented in the form of **IPython/Jup
| Implement depth-first search (pre-, in-, post-order) | [Challenge](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_dfs/dfs_challenge.ipynb)│[Solution](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_dfs/dfs_solution.ipynb) | | Implement depth-first search (pre-, in-, post-order) | [Challenge](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_dfs/dfs_challenge.ipynb)│[Solution](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_dfs/dfs_solution.ipynb) |
| Implement breadth-first search | [Challenge](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_bfs/bfs_challenge.ipynb)│[Solution](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_bfs/bfs_solution.ipynb) | | Implement breadth-first search | [Challenge](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_bfs/bfs_challenge.ipynb)│[Solution](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_bfs/bfs_solution.ipynb) |
| Determine the height of a tree | [Challenge](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_height/height_challenge.ipynb)│[Solution](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_height/height_solution.ipynb) | | Determine the height of a tree | [Challenge](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_height/height_challenge.ipynb)│[Solution](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/tree_height/height_solution.ipynb) |
| Implement a basic graph | [Challenge](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/graph/graph_challenge.ipynb)│[Solution](http://nbviewer.ipython.org/github/donnemartin/interactive-coding-challenges/blob/master/graphs_trees/graph/graph_solution.ipynb) |
| Print a tree using pre-order traversal without recursion | [Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md)│[Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md) | | Print a tree using pre-order traversal without recursion | [Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md)│[Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md) |
| Determine the lowest common ancestor of two nodes | [Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md)│[Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md) | | Determine the lowest common ancestor of two nodes | [Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md)│[Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md) |
| Transform a binary tree into a heap | [Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md)│[Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md) | | Transform a binary tree into a heap | [Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md)│[Contribute](https://github.com/donnemartin/interactive-coding-challenges/blob/master/CONTRIBUTING.md) |

View File

View File

@ -0,0 +1,34 @@
# Python 2 users: Run pip install enum34
from enum import Enum
class State(Enum):
unvisited = 1
visited = 2
visiting = 3
class Node:
def __init__(self, id):
self.id = id
self.state = State.unvisited
self.connections = {}
class Graph:
def __init__(self):
self.nodes = {}
def add_node(self, id):
node = Node(id)
self.nodes[id] = node
return node
def add_edge(self, source, dest, weight=0):
if source not in self.nodes:
self.add_node(source)
if dest not in self.nodes:
self.add_node(dest)
self.nodes[source].connections[self.nodes[dest]] = weight

View File

@ -0,0 +1,217 @@
{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<small><i>This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges).</i></small>"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Challenge Notebook"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Problem: Implement a basic graph.\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",
"* I plan to use a Node and Graph class. \n",
" * Node will keep track of its id, visit state, and connections. \n",
" * Connections will be a dictionary with the key = node id and value being the edge weight\n",
" * Graph will hold all of the nodes and have functions to add nodes and edges. \n",
" * Is this in line with what you have in mind?\n",
" * Yes"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Test Cases\n",
"\n",
"Input:\n",
"* `add_edge(source, destination, weight)`\n",
"\n",
"```\n",
"graph.add_edge(0, 1, 5)\n",
"graph.add_edge(0, 5, 2)\n",
"graph.add_edge(1, 2, 3)\n",
"graph.add_edge(2, 3, 4)\n",
"graph.add_edge(3, 4, 5)\n",
"graph.add_edge(3, 5, 6)\n",
"graph.add_edge(4, 0, 7)\n",
"graph.add_edge(5, 4, 8)\n",
"graph.add_edge(5, 2, 9)\n",
"```\n",
"\n",
"Result:\n",
"* `source` and `destination` nodes within `graph` are connected with specified `weight`."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Algorithm\n",
"\n",
"Refer to the [Solution Notebook](https://github.com/donnemartin/interactive-coding-challenges/graphs_trees/graphs/graph_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": [
"# Python 2 users: Run pip install enum34\n",
"from enum import Enum\n",
"\n",
"\n",
"class State(Enum):\n",
" unvisited = 1\n",
" visited = 2\n",
" visiting = 3\n",
"\n",
"\n",
"class Node:\n",
"\n",
" def __init__(self, id):\n",
" # TODO: Implement me\n",
"\n",
"\n",
"class Graph:\n",
"\n",
" def __init__(self):\n",
" # TODO: Implement me\n",
"\n",
" def add_node(self, id):\n",
" # TODO: Implement me\n",
"\n",
" def add_edge(self, source, dest, weight=0):\n",
" # TODO: Implement me"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Unit Test"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"**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_graph.py\n",
"from nose.tools import assert_equal\n",
"\n",
"\n",
"class TestGraph(object):\n",
"\n",
" def test_graph(self):\n",
" graph = Graph()\n",
" for key in range(0, 6):\n",
" graph.add_node(key)\n",
" graph.add_edge(0, 1, 5)\n",
" graph.add_edge(0, 5, 2)\n",
" graph.add_edge(1, 2, 3)\n",
" graph.add_edge(2, 3, 4)\n",
" graph.add_edge(3, 4, 5)\n",
" graph.add_edge(3, 5, 6)\n",
" graph.add_edge(4, 0, 7)\n",
" graph.add_edge(5, 4, 8)\n",
" graph.add_edge(5, 2, 9)\n",
"\n",
" assert_equal(graph.nodes[0].connections[graph.nodes[1]], 5)\n",
" assert_equal(graph.nodes[0].connections[graph.nodes[5]], 2)\n",
" assert_equal(graph.nodes[1].connections[graph.nodes[2]], 3)\n",
" assert_equal(graph.nodes[2].connections[graph.nodes[3]], 4)\n",
" assert_equal(graph.nodes[3].connections[graph.nodes[4]], 5)\n",
" assert_equal(graph.nodes[3].connections[graph.nodes[5]], 6)\n",
" assert_equal(graph.nodes[4].connections[graph.nodes[0]], 7)\n",
" assert_equal(graph.nodes[5].connections[graph.nodes[4]], 8)\n",
" assert_equal(graph.nodes[5].connections[graph.nodes[2]], 9)\n",
"\n",
" print('Success: test_graph')\n",
"\n",
"\n",
"def main():\n",
" test = TestGraph()\n",
" test.test_graph()\n",
"\n",
"\n",
"if __name__ == '__main__':\n",
" main()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Solution Notebook\n",
"\n",
"Review the [Solution Notebook](https://github.com/donnemartin/interactive-coding-challenges/graphs_trees/graphs/graph_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
}

View File

@ -0,0 +1,252 @@
{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"<small><i>This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges).</i></small>"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Solution Notebook"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Problem: Implement a basic graph.\n",
"\n",
"* [Constraints](#Constraints)\n",
"* [Test Cases](#Test-Cases)\n",
"* [Algorithm](#Algorithm)\n",
"* [Code](#Code)\n",
"* [Unit Test](#Unit-Test)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Constraints\n",
"\n",
"* I plan to use a Node and Graph class. \n",
" * Node will keep track of its id, visit state, and connections. \n",
" * Connections will be a dictionary with the key = node id and value being the edge weight\n",
" * Graph will hold all of the nodes and have functions to add nodes and edges. \n",
" * Is this in line with what you have in mind?\n",
" * Yes"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Test Cases\n",
"\n",
"Input:\n",
"* `add_edge(source, destination, weight)`\n",
"\n",
"```\n",
"graph.add_edge(0, 1, 5)\n",
"graph.add_edge(0, 5, 2)\n",
"graph.add_edge(1, 2, 3)\n",
"graph.add_edge(2, 3, 4)\n",
"graph.add_edge(3, 4, 5)\n",
"graph.add_edge(3, 5, 6)\n",
"graph.add_edge(4, 0, 7)\n",
"graph.add_edge(5, 4, 8)\n",
"graph.add_edge(5, 2, 9)\n",
"```\n",
"\n",
"Result:\n",
"* `source` and `destination` nodes within `graph` are connected with specified `weight`."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Algorithm\n",
"\n",
"### add_node\n",
"\n",
"* Create a node with the input id\n",
"* Add the newly created node to the list of nodes\n",
"\n",
"Complexity:\n",
"* Time: O(1)\n",
"* Space: O(1)\n",
"\n",
"### add_edge\n",
"\n",
"* If the source node is not in the list of nodes, add it\n",
"* If the dest node is not in the list of nodes, add it\n",
"* Add a connection from the source node to the dest node with the given edge weight\n",
"\n",
"Complexity:\n",
"* Time: O(1)\n",
"* Space: O(1)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Code"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"# Python 2 users: Run pip install enum34\n",
"from enum import Enum\n",
"\n",
"\n",
"class State(Enum):\n",
" unvisited = 1\n",
" visited = 2\n",
" visiting = 3\n",
"\n",
"\n",
"class Node:\n",
"\n",
" def __init__(self, id):\n",
" self.id = id\n",
" self.state = State.unvisited\n",
" self.connections = {}\n",
"\n",
"\n",
"class Graph:\n",
"\n",
" def __init__(self):\n",
" self.nodes = {}\n",
"\n",
" def add_node(self, id):\n",
" node = Node(id)\n",
" self.nodes[id] = node\n",
" return node\n",
"\n",
" def add_edge(self, source, dest, weight=0):\n",
" if source not in self.nodes:\n",
" self.add_node(source)\n",
" if dest not in self.nodes:\n",
" self.add_node(dest)\n",
" self.nodes[source].connections[self.nodes[dest]] = weight"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Unit Test"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Overwriting test_graph.py\n"
]
}
],
"source": [
"%%writefile test_graph.py\n",
"from nose.tools import assert_equal\n",
"\n",
"\n",
"class TestGraph(object):\n",
"\n",
" def test_graph(self):\n",
" graph = Graph()\n",
" for key in range(0, 6):\n",
" graph.add_node(key)\n",
" graph.add_edge(0, 1, 5)\n",
" graph.add_edge(0, 5, 2)\n",
" graph.add_edge(1, 2, 3)\n",
" graph.add_edge(2, 3, 4)\n",
" graph.add_edge(3, 4, 5)\n",
" graph.add_edge(3, 5, 6)\n",
" graph.add_edge(4, 0, 7)\n",
" graph.add_edge(5, 4, 8)\n",
" graph.add_edge(5, 2, 9)\n",
"\n",
" assert_equal(graph.nodes[0].connections[graph.nodes[1]], 5)\n",
" assert_equal(graph.nodes[0].connections[graph.nodes[5]], 2)\n",
" assert_equal(graph.nodes[1].connections[graph.nodes[2]], 3)\n",
" assert_equal(graph.nodes[2].connections[graph.nodes[3]], 4)\n",
" assert_equal(graph.nodes[3].connections[graph.nodes[4]], 5)\n",
" assert_equal(graph.nodes[3].connections[graph.nodes[5]], 6)\n",
" assert_equal(graph.nodes[4].connections[graph.nodes[0]], 7)\n",
" assert_equal(graph.nodes[5].connections[graph.nodes[4]], 8)\n",
" assert_equal(graph.nodes[5].connections[graph.nodes[2]], 9)\n",
"\n",
" print('Success: test_graph')\n",
"\n",
"\n",
"def main():\n",
" test = TestGraph()\n",
" test.test_graph()\n",
"\n",
"\n",
"if __name__ == '__main__':\n",
" main()"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"Success: test_graph\n"
]
}
],
"source": [
"%run -i test_graph.py"
]
}
],
"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
}

View File

@ -0,0 +1,39 @@
from nose.tools import assert_equal
class TestGraph(object):
def test_graph(self):
graph = Graph()
for key in range(0, 6):
graph.add_node(key)
graph.add_edge(0, 1, 5)
graph.add_edge(0, 5, 2)
graph.add_edge(1, 2, 3)
graph.add_edge(2, 3, 4)
graph.add_edge(3, 4, 5)
graph.add_edge(3, 5, 6)
graph.add_edge(4, 0, 7)
graph.add_edge(5, 4, 8)
graph.add_edge(5, 2, 9)
assert_equal(graph.nodes[0].connections[graph.nodes[1]], 5)
assert_equal(graph.nodes[0].connections[graph.nodes[5]], 2)
assert_equal(graph.nodes[1].connections[graph.nodes[2]], 3)
assert_equal(graph.nodes[2].connections[graph.nodes[3]], 4)
assert_equal(graph.nodes[3].connections[graph.nodes[4]], 5)
assert_equal(graph.nodes[3].connections[graph.nodes[5]], 6)
assert_equal(graph.nodes[4].connections[graph.nodes[0]], 7)
assert_equal(graph.nodes[5].connections[graph.nodes[4]], 8)
assert_equal(graph.nodes[5].connections[graph.nodes[2]], 9)
print('Success: test_graph')
def main():
test = TestGraph()
test.test_graph()
if __name__ == '__main__':
main()