47 lines
1.2 KiB
Python
47 lines
1.2 KiB
Python
# implementation of an undirected graph using Adjacency Lists
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class Vertex:
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def __init__(self, n):
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self.name = n
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self.neighbors = list()
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def add_neighbor(self, v):
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if v not in self.neighbors:
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self.neighbors.append(v)
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self.neighbors.sort()
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class Graph:
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vertices = {}
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def add_vertex(self, vertex):
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if isinstance(vertex, Vertex) and vertex.name not in self.vertices:
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self.vertices[vertex.name] = vertex
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return True
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else:
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return False
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def add_edge(self, u, v):
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if u in self.vertices and v in self.vertices:
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# my YouTube video shows a silly for loop here, but this is a much faster way to do it
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self.vertices[u].add_neighbor(v)
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self.vertices[v].add_neighbor(u)
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return True
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else:
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return False
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def print_graph(self):
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for key in sorted(list(self.vertices.keys())):
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print(key + str(self.vertices[key].neighbors))
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g = Graph()
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# print(str(len(g.vertices)))
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a = Vertex('A')
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g.add_vertex(a)
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g.add_vertex(Vertex('B'))
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for i in range(ord('A'), ord('K')):
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g.add_vertex(Vertex(chr(i)))
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edges = ['AB', 'AE', 'BF', 'CG', 'DE', 'DH', 'EH', 'FG', 'FI', 'FJ', 'GJ', 'HI']
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for edge in edges:
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g.add_edge(edge[:1], edge[1:])
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g.print_graph() |