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Rework graph challenge and solution (#90)

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Donne Martin
2016-07-04 07:16:15 -04:00
committed by GitHub
parent 618eeedfe3
commit cb660acd13
4 changed files with 254 additions and 118 deletions
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89
graphs_trees/graph/graph_challenge.ipynb
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@@ -39,6 +39,12 @@
"* Do the edges have weights?\n",
" * Yes\n",
"* Can we assume the inputs are valid?\n",
" * Yes\n",
"* If we try to add a node that already exists, do we just do nothing?\n",
" * Yes\n",
"* If we try to delete a node that doesn't exist, do we just do nothing?\n",
" * Yes\n",
"* Can we assume this fits memory?\n",
" * Yes"
]
},
@@ -94,24 +100,43 @@
},
"outputs": [],
"source": [
"from enum import Enum # Python 2 users: Run pip install enum34\n",
"\n",
"\n",
"class State(Enum):\n",
" unvisited = 0\n",
" visiting = 1\n",
" visited = 2\n",
"\n",
"\n",
"class Node:\n",
"\n",
" def __init__(self, id):\n",
" # TODO: Implement me\n",
" self.adjacent = {} # key = node, val = weight\n",
" def __init__(self, key):\n",
" self.key = key\n",
" self.visit_state = State.unvisited\n",
" self.incoming_edges = 0\n",
" self.adj_nodes = {} # Key = key, val = Node\n",
" self.adj_weights = {} # Key = Node, val = weight\n",
"\n",
" def __str__(self):\n",
" def __repr__(self):\n",
" return str(self.id)\n",
"\n",
" def __lt__(self, left, right):\n",
" return left.id < right.id\n",
"\n",
" def add_neighbor(self, neighbor, weight=0):\n",
" # TODO: Implement me\n",
" pass\n",
"\n",
" def remove_neighbor(self, neighbor):\n",
" # TODO: Implement me\n",
" pass\n",
"\n",
"\n",
"class Graph:\n",
"\n",
" def __init__(self):\n",
" # TODO: Implement me\n",
" self.nodes = {} # key = node id, val = node\n",
" self.nodes = {} # Key = key, val = Node\n",
"\n",
" def add_node(self, id):\n",
" # TODO: Implement me\n",
@@ -156,13 +181,12 @@
"\n",
" def create_graph(self):\n",
" graph = Graph()\n",
" for id in range(0, 6):\n",
" graph.add_node(id)\n",
" for key in range(0, 6):\n",
" graph.add_node(key)\n",
" return graph\n",
"\n",
" def test_graph(self):\n",
" graph = self.create_graph()\n",
"\n",
" graph.add_edge(0, 1, weight=5)\n",
" graph.add_edge(0, 5, weight=2)\n",
" graph.add_edge(1, 2, weight=3)\n",
@@ -173,33 +197,46 @@
" graph.add_edge(5, 4, weight=8)\n",
" graph.add_edge(5, 2, weight=9)\n",
"\n",
" assert_equal(graph.nodes[0].adjacent[graph.nodes[1]], 5)\n",
" assert_equal(graph.nodes[0].adjacent[graph.nodes[5]], 2)\n",
" assert_equal(graph.nodes[1].adjacent[graph.nodes[2]], 3)\n",
" assert_equal(graph.nodes[2].adjacent[graph.nodes[3]], 4)\n",
" assert_equal(graph.nodes[3].adjacent[graph.nodes[4]], 5)\n",
" assert_equal(graph.nodes[3].adjacent[graph.nodes[5]], 6)\n",
" assert_equal(graph.nodes[4].adjacent[graph.nodes[0]], 7)\n",
" assert_equal(graph.nodes[5].adjacent[graph.nodes[4]], 8)\n",
" assert_equal(graph.nodes[5].adjacent[graph.nodes[2]], 9)\n",
" assert_equal(graph.nodes[0].adj_weights[graph.nodes[1].key], 5)\n",
" assert_equal(graph.nodes[0].adj_weights[graph.nodes[5].key], 2)\n",
" assert_equal(graph.nodes[1].adj_weights[graph.nodes[2].key], 3)\n",
" assert_equal(graph.nodes[2].adj_weights[graph.nodes[3].key], 4)\n",
" assert_equal(graph.nodes[3].adj_weights[graph.nodes[4].key], 5)\n",
" assert_equal(graph.nodes[3].adj_weights[graph.nodes[5].key], 6)\n",
" assert_equal(graph.nodes[4].adj_weights[graph.nodes[0].key], 7)\n",
" assert_equal(graph.nodes[5].adj_weights[graph.nodes[4].key], 8)\n",
" assert_equal(graph.nodes[5].adj_weights[graph.nodes[2].key], 9)\n",
"\n",
" assert_equal(graph.nodes[0].incoming_edges, 1)\n",
" assert_equal(graph.nodes[1].incoming_edges, 1)\n",
" assert_equal(graph.nodes[2].incoming_edges, 2)\n",
" assert_equal(graph.nodes[3].incoming_edges, 1)\n",
" assert_equal(graph.nodes[4].incoming_edges, 2)\n",
" assert_equal(graph.nodes[5].incoming_edges, 2)\n",
"\n",
" graph.nodes[0].remove_neighbor(graph.nodes[1])\n",
" assert_equal(graph.nodes[1].incoming_edges, 0)\n",
" graph.nodes[3].remove_neighbor(graph.nodes[4])\n",
" assert_equal(graph.nodes[4].incoming_edges, 1)\n",
"\n",
" assert_equal(graph.nodes[0] < graph.nodes[1], True)\n",
"\n",
" print('Success: test_graph')\n",
"\n",
" def test_graph_undirected(self):\n",
" graph = self.create_graph()\n",
"\n",
" graph.add_undirected_edge(0, 1, weight=5)\n",
" graph.add_undirected_edge(0, 5, weight=2)\n",
" graph.add_undirected_edge(1, 2, weight=3)\n",
"\n",
" assert_equal(graph.nodes[0].adjacent[graph.nodes[1]], 5)\n",
" assert_equal(graph.nodes[1].adjacent[graph.nodes[0]], 5)\n",
" assert_equal(graph.nodes[0].adjacent[graph.nodes[5]], 2)\n",
" assert_equal(graph.nodes[5].adjacent[graph.nodes[0]], 2)\n",
" assert_equal(graph.nodes[1].adjacent[graph.nodes[2]], 3)\n",
" assert_equal(graph.nodes[2].adjacent[graph.nodes[1]], 3)\n",
" assert_equal(graph.nodes[0].adj_weights[graph.nodes[1].key], 5)\n",
" assert_equal(graph.nodes[1].adj_weights[graph.nodes[0].key], 5)\n",
" assert_equal(graph.nodes[0].adj_weights[graph.nodes[5].key], 2)\n",
" assert_equal(graph.nodes[5].adj_weights[graph.nodes[0].key], 2)\n",
" assert_equal(graph.nodes[1].adj_weights[graph.nodes[2].key], 3)\n",
" assert_equal(graph.nodes[2].adj_weights[graph.nodes[1].key], 3)\n",
"\n",
" print('Success: test_graph')\n",
" print('Success: test_graph_undirected')\n",
"\n",
"\n",
"def main():\n",