mirror of
https://github.com/donnemartin/interactive-coding-challenges.git
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Added basic graph implementation challenge.
This commit is contained in:
Donne Martin
parent
9d1a68fb40
commit
92e0318952
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@ -207,6 +207,7 @@ Challenges, solutions, and unit tests are presented in the form of **IPython/Jup
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| 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) |
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| 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) |
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| 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) |
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| 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) |
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| 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) |
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| 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) |
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| 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) |
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0
graphs_trees/graph/__init__.py
Normal file
0
graphs_trees/graph/__init__.py
Normal file
34
graphs_trees/graph/graph.py
Normal file
34
graphs_trees/graph/graph.py
Normal file
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@ -0,0 +1,34 @@
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# Python 2 users: Run pip install enum34
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from enum import Enum
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class State(Enum):
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unvisited = 1
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visited = 2
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visiting = 3
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class Node:
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def __init__(self, id):
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self.id = id
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self.state = State.unvisited
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self.connections = {}
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class Graph:
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def __init__(self):
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self.nodes = {}
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def add_node(self, id):
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node = Node(id)
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self.nodes[id] = node
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return node
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def add_edge(self, source, dest, weight=0):
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if source not in self.nodes:
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self.add_node(source)
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if dest not in self.nodes:
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self.add_node(dest)
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self.nodes[source].connections[self.nodes[dest]] = weight
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217
graphs_trees/graph/graph_challenge.ipynb
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217
graphs_trees/graph/graph_challenge.ipynb
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@ -0,0 +1,217 @@
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{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"<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>"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"# Challenge Notebook"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Problem: Implement a basic graph.\n",
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"\n",
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"* [Constraints](#Constraints)\n",
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"* [Test Cases](#Test-Cases)\n",
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"* [Algorithm](#Algorithm)\n",
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"* [Code](#Code)\n",
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"* [Unit Test](#Unit-Test)\n",
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"* [Solution Notebook](#Solution-Notebook)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Constraints\n",
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"\n",
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"* I plan to use a Node and Graph class. \n",
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" * Node will keep track of its id, visit state, and connections. \n",
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" * Connections will be a dictionary with the key = node id and value being the edge weight\n",
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" * Graph will hold all of the nodes and have functions to add nodes and edges. \n",
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" * Is this in line with what you have in mind?\n",
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" * Yes"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Test Cases\n",
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"\n",
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"Input:\n",
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"* `add_edge(source, destination, weight)`\n",
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"\n",
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"```\n",
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"graph.add_edge(0, 1, 5)\n",
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"graph.add_edge(0, 5, 2)\n",
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"graph.add_edge(1, 2, 3)\n",
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"graph.add_edge(2, 3, 4)\n",
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"graph.add_edge(3, 4, 5)\n",
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"graph.add_edge(3, 5, 6)\n",
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"graph.add_edge(4, 0, 7)\n",
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"graph.add_edge(5, 4, 8)\n",
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"graph.add_edge(5, 2, 9)\n",
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"```\n",
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"\n",
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"Result:\n",
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"* `source` and `destination` nodes within `graph` are connected with specified `weight`."
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Algorithm\n",
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"\n",
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"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."
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Code"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"collapsed": false
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},
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"outputs": [],
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"source": [
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"# Python 2 users: Run pip install enum34\n",
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"from enum import Enum\n",
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"\n",
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"\n",
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"class State(Enum):\n",
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" unvisited = 1\n",
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" visited = 2\n",
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" visiting = 3\n",
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"\n",
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"\n",
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"class Node:\n",
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"\n",
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" def __init__(self, id):\n",
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" # TODO: Implement me\n",
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"\n",
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"\n",
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"class Graph:\n",
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"\n",
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" def __init__(self):\n",
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" # TODO: Implement me\n",
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"\n",
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" def add_node(self, id):\n",
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" # TODO: Implement me\n",
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"\n",
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" def add_edge(self, source, dest, weight=0):\n",
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" # TODO: Implement me"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Unit Test"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"**The following unit test is expected to fail until you solve the challenge.**"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {
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"collapsed": false
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},
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"outputs": [],
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"source": [
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"# %load test_graph.py\n",
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"from nose.tools import assert_equal\n",
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"\n",
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"\n",
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"class TestGraph(object):\n",
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"\n",
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" def test_graph(self):\n",
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" graph = Graph()\n",
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" for key in range(0, 6):\n",
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" graph.add_node(key)\n",
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" graph.add_edge(0, 1, 5)\n",
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" graph.add_edge(0, 5, 2)\n",
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" graph.add_edge(1, 2, 3)\n",
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" graph.add_edge(2, 3, 4)\n",
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" graph.add_edge(3, 4, 5)\n",
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" graph.add_edge(3, 5, 6)\n",
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" graph.add_edge(4, 0, 7)\n",
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" graph.add_edge(5, 4, 8)\n",
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" graph.add_edge(5, 2, 9)\n",
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"\n",
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" assert_equal(graph.nodes[0].connections[graph.nodes[1]], 5)\n",
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" assert_equal(graph.nodes[0].connections[graph.nodes[5]], 2)\n",
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" assert_equal(graph.nodes[1].connections[graph.nodes[2]], 3)\n",
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" assert_equal(graph.nodes[2].connections[graph.nodes[3]], 4)\n",
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" assert_equal(graph.nodes[3].connections[graph.nodes[4]], 5)\n",
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" assert_equal(graph.nodes[3].connections[graph.nodes[5]], 6)\n",
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" assert_equal(graph.nodes[4].connections[graph.nodes[0]], 7)\n",
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" assert_equal(graph.nodes[5].connections[graph.nodes[4]], 8)\n",
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" assert_equal(graph.nodes[5].connections[graph.nodes[2]], 9)\n",
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"\n",
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" print('Success: test_graph')\n",
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"\n",
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"\n",
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"def main():\n",
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" test = TestGraph()\n",
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" test.test_graph()\n",
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"\n",
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"\n",
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"if __name__ == '__main__':\n",
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" main()"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Solution Notebook\n",
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"\n",
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"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."
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]
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}
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],
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"metadata": {
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"kernelspec": {
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"display_name": "Python 2",
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"language": "python",
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"name": "python2"
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},
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"language_info": {
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"codemirror_mode": {
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"name": "ipython",
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"version": 2
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},
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"file_extension": ".py",
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"mimetype": "text/x-python",
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"name": "python",
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"nbconvert_exporter": "python",
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"pygments_lexer": "ipython2",
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"version": "2.7.10"
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}
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},
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"nbformat": 4,
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"nbformat_minor": 0
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}
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252
graphs_trees/graph/graph_solution.ipynb
Normal file
252
graphs_trees/graph/graph_solution.ipynb
Normal file
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@ -0,0 +1,252 @@
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{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {},
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||||
"source": [
|
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"<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>"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"# Solution Notebook"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Problem: Implement a basic graph.\n",
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"\n",
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"* [Constraints](#Constraints)\n",
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"* [Test Cases](#Test-Cases)\n",
|
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"* [Algorithm](#Algorithm)\n",
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"* [Code](#Code)\n",
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"* [Unit Test](#Unit-Test)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
|
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"## Constraints\n",
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"\n",
|
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"* I plan to use a Node and Graph class. \n",
|
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" * Node will keep track of its id, visit state, and connections. \n",
|
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" * Connections will be a dictionary with the key = node id and value being the edge weight\n",
|
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" * Graph will hold all of the nodes and have functions to add nodes and edges. \n",
|
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" * Is this in line with what you have in mind?\n",
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" * Yes"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Test Cases\n",
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"\n",
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"Input:\n",
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"* `add_edge(source, destination, weight)`\n",
|
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"\n",
|
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"```\n",
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"graph.add_edge(0, 1, 5)\n",
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"graph.add_edge(0, 5, 2)\n",
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"graph.add_edge(1, 2, 3)\n",
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"graph.add_edge(2, 3, 4)\n",
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"graph.add_edge(3, 4, 5)\n",
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"graph.add_edge(3, 5, 6)\n",
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"graph.add_edge(4, 0, 7)\n",
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"graph.add_edge(5, 4, 8)\n",
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"graph.add_edge(5, 2, 9)\n",
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"```\n",
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"\n",
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"Result:\n",
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"* `source` and `destination` nodes within `graph` are connected with specified `weight`."
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Algorithm\n",
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"\n",
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"### add_node\n",
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"\n",
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"* Create a node with the input id\n",
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"* Add the newly created node to the list of nodes\n",
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"\n",
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"Complexity:\n",
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"* Time: O(1)\n",
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"* Space: O(1)\n",
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"\n",
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"### add_edge\n",
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"\n",
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"* If the source node is not in the list of nodes, add it\n",
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"* If the dest node is not in the list of nodes, add it\n",
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"* Add a connection from the source node to the dest node with the given edge weight\n",
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"\n",
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"Complexity:\n",
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"* Time: O(1)\n",
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"* Space: O(1)"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Code"
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]
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},
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{
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"cell_type": "code",
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"execution_count": 1,
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"metadata": {
|
||||
"collapsed": true
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||||
},
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"outputs": [],
|
||||
"source": [
|
||||
"# Python 2 users: Run pip install enum34\n",
|
||||
"from enum import Enum\n",
|
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"\n",
|
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"\n",
|
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"class State(Enum):\n",
|
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" unvisited = 1\n",
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" visited = 2\n",
|
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" visiting = 3\n",
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"\n",
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"\n",
|
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"class Node:\n",
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"\n",
|
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" def __init__(self, id):\n",
|
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" self.id = id\n",
|
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" self.state = State.unvisited\n",
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" self.connections = {}\n",
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"\n",
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"\n",
|
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"class Graph:\n",
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"\n",
|
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" def __init__(self):\n",
|
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" self.nodes = {}\n",
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"\n",
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" def add_node(self, id):\n",
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" node = Node(id)\n",
|
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" self.nodes[id] = node\n",
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" return node\n",
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"\n",
|
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" def add_edge(self, source, dest, weight=0):\n",
|
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" if source not in self.nodes:\n",
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" self.add_node(source)\n",
|
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" if dest not in self.nodes:\n",
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" self.add_node(dest)\n",
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" self.nodes[source].connections[self.nodes[dest]] = weight"
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]
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},
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{
|
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"cell_type": "markdown",
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"metadata": {},
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"source": [
|
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"## Unit Test"
|
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]
|
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},
|
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{
|
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"cell_type": "code",
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"execution_count": 2,
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"metadata": {
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"collapsed": false
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},
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"outputs": [
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{
|
||||
"name": "stdout",
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"output_type": "stream",
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"text": [
|
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"Overwriting test_graph.py\n"
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]
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}
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],
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"source": [
|
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"%%writefile test_graph.py\n",
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"from nose.tools import assert_equal\n",
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"\n",
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"\n",
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"class TestGraph(object):\n",
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"\n",
|
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" def test_graph(self):\n",
|
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" graph = Graph()\n",
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" for key in range(0, 6):\n",
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" graph.add_node(key)\n",
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" graph.add_edge(0, 1, 5)\n",
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" 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
|
||||
}
|
||||
39
graphs_trees/graph/test_graph.py
Normal file
39
graphs_trees/graph/test_graph.py
Normal 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()
|
||||
Loading…
Reference in New Issue
Block a user