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@ericcgu
Forked from anirudhjayaraman/graphUndirected.ipynb
Created July 12, 2018 16:21
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Python Implementation of Undirected Graphs (Adjacency List and Adjacency Matrix)
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"name": "stdout",
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"text": [
"{}\n",
"\n",
"{}\n",
"\n",
"\n",
"[\"A:['B', 'C', 'E']\", \"C:['A', 'B', 'D', 'E']\", \"B:['A', 'C', 'D']\", \"E:['A', 'C']\", \"D:['B', 'C']\"]\n",
"\n",
"[[ 0. 1. 1. 0. 1.]\n",
" [ 1. 0. 1. 1. 0.]\n",
" [ 1. 1. 0. 1. 1.]\n",
" [ 0. 1. 1. 0. 0.]\n",
" [ 1. 0. 1. 0. 0.]]\n"
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"source": [
"class Vertex:\n",
" def __init__(self, vertex):\n",
" self.name = vertex\n",
" self.neighbors = []\n",
" \n",
" def add_neighbor(self, neighbor):\n",
" if isinstance(neighbor, Vertex):\n",
" if neighbor.name not in self.neighbors:\n",
" self.neighbors.append(neighbor.name)\n",
" neighbor.neighbors.append(self.name)\n",
" self.neighbors = sorted(self.neighbors)\n",
" neighbor.neighbors = sorted(neighbor.neighbors)\n",
" else:\n",
" return False\n",
" \n",
" def add_neighbors(self, neighbors):\n",
" for neighbor in neighbors:\n",
" if isinstance(neighbor, Vertex):\n",
" if neighbor.name not in self.neighbors:\n",
" self.neighbors.append(neighbor.name)\n",
" neighbor.neighbors.append(self.name)\n",
" self.neighbors = sorted(self.neighbors)\n",
" neighbor.neighbors = sorted(neighbor.neighbors)\n",
" else:\n",
" return False\n",
" \n",
" def __repr__(self):\n",
" return str(self.neighbors)\n",
"\n",
"\n",
"class Graph:\n",
" def __init__(self):\n",
" self.vertices = {}\n",
" \n",
" def add_vertex(self, vertex):\n",
" if isinstance(vertex, Vertex):\n",
" self.vertices[vertex.name] = vertex.neighbors\n",
"\n",
" \n",
" def add_vertices(self, vertices):\n",
" for vertex in vertices:\n",
" if isinstance(vertex, Vertex):\n",
" self.vertices[vertex.name] = vertex.neighbors\n",
"\n",
" \n",
" def add_edge(self, vertex_from, vertex_to):\n",
" if isinstance(vertex_from, Vertex) and isinstance(vertex_to, Vertex):\n",
" vertex_from.add_neighbor(vertex_to)\n",
" if isinstance(vertex_from, Vertex) and isinstance(vertex_to, Vertex):\n",
" self.vertices[vertex_from.name] = vertex_from.neighbors\n",
" self.vertices[vertex_to.name] = vertex_to.neighbors\n",
" \n",
" def add_edges(self, edges):\n",
" for edge in edges:\n",
" self.add_edge(edge[0],edge[1]) \n",
" \n",
" def adjacencyList(self):\n",
" if len(self.vertices) >= 1:\n",
" return [str(key) + \":\" + str(self.vertices[key]) for key in self.vertices.keys()] \n",
" else:\n",
" return dict()\n",
" \n",
" def adjacencyMatrix(self):\n",
" if len(self.vertices) >= 1:\n",
" self.vertex_names = sorted(g.vertices.keys())\n",
" self.vertex_indices = dict(zip(self.vertex_names, range(len(self.vertex_names)))) \n",
" import numpy as np\n",
" self.adjacency_matrix = np.zeros(shape=(len(self.vertices),len(self.vertices)))\n",
" for i in range(len(self.vertex_names)):\n",
" for j in range(i, len(self.vertices)):\n",
" for el in g.vertices[self.vertex_names[i]]:\n",
" j = g.vertex_indices[el]\n",
" self.adjacency_matrix[i,j] = 1\n",
" return self.adjacency_matrix\n",
" else:\n",
" return dict() \n",
" \n",
"\n",
"def graph(g):\n",
" \"\"\" Function to print a graph as adjacency list and adjacency matrix. \"\"\"\n",
" return str(g.adjacencyList()) + '\\n' + '\\n' + str(g.adjacencyMatrix())\n",
"\n",
"###################################################################################\n",
"\n",
"a = Vertex('A')\n",
"b = Vertex('B')\n",
"c = Vertex('C')\n",
"d = Vertex('D')\n",
"e = Vertex('E')\n",
"\n",
"a.add_neighbors([b,c,e]) \n",
"b.add_neighbors([a,c])\n",
"c.add_neighbors([b,d,a,e])\n",
"d.add_neighbor(c)\n",
"e.add_neighbors([a,c])\n",
" \n",
" \n",
"g = Graph()\n",
"print graph(g)\n",
"print \n",
"g.add_vertices([a,b,c,d,e])\n",
"g.add_edge(b,d)\n",
"print\n",
"print graph(g)"
]
}
],
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