graph implementations in Python, and updated LinkedLists

Author: joeyajames

LinkedLists.py

@@ -61,6 +61,9 @@ def find (self, d):
 myList.add(5)
 myList.add(8)
 myList.add(12)
+print("size="+str(myList.get_size()))
 myList.remove(8)
+print("size="+str(myList.get_size()))
 print(myList.remove(12))
+print("size="+str(myList.get_size()))
 print(myList.find(5))

graph_adjacency-list.py

@@ -0,0 +1,48 @@
+class Vertex:
+	def __init__(self, n):
+		self.name = n
+		self.neighbors = list()
+	
+	def add_neighbor(self, v):
+		if v not in self.neighbors:
+			self.neighbors.append(v)
+			self.neighbors.sort()
+
+class Graph:
+	vertices = {}
+	
+	def add_vertex(self, vertex):
+		if isinstance(vertex, Vertex) and vertex.name not in self.vertices:
+			self.vertices[vertex.name] = vertex
+			return True
+		else:
+			return False
+	
+	def add_edge(self, u, v):
+		if u in self.vertices and v in self.vertices:
+			for key, value in self.vertices.items():
+				if key == u:
+					value.add_neighbor(v)
+				if key == v:
+					value.add_neighbor(u)
+			return True
+		else:
+			return False
+			
+	def print_graph(self):
+		for key in sorted(list(self.vertices.keys())):
+			print(key + str(self.vertices[key].neighbors))
+
+g = Graph()
+# print(str(len(g.vertices)))
+a = Vertex('A')
+g.add_vertex(a)
+g.add_vertex(Vertex('B'))
+for i in range(ord('A'), ord('K')):
+	g.add_vertex(Vertex(chr(i)))
+
+edges = ['AB', 'AE', 'BF', 'CG', 'DE', 'DH', 'EH', 'FG', 'FI', 'FJ', 'GJ', 'HI']
+for edge in edges:
+	g.add_edge(edge[:1], edge[1:])
+
+g.print_graph()

graph_adjacency-matrix.py

@@ -0,0 +1,49 @@
+# implementation of an undirected graph using Adjacency Matrix, with weighted or unweighted edges
+class Vertex:
+	def __init__(self, n):
+		self.name = n
+
+class Graph:
+	vertices = {}
+	edges = []
+	edge_indices = {}
+	
+	def add_vertex(self, vertex):
+		if isinstance(vertex, Vertex) and vertex.name not in self.vertices:
+			self.vertices[vertex.name] = vertex
+			for row in self.edges:
+				row.append(0)
+			self.edges.append([0] * (len(self.edges)+1))
+			self.edge_indices[vertex.name] = len(self.edge_indices)
+			return True
+		else:
+			return False
+	
+	def add_edge(self, u, v, weight=1):
+		if u in self.vertices and v in self.vertices:
+			self.edges[self.edge_indices[u]][self.edge_indices[v]] = weight
+			self.edges[self.edge_indices[v]][self.edge_indices[u]] = weight
+			return True
+		else:
+			return False
+			
+	def print_graph(self):
+		for v, i in sorted(self.edge_indices.items()):
+			print(v + ' ', end='')
+			for j in range(len(self.edges)):
+				print(self.edges[i][j], end='')
+			print(' ')    
+
+g = Graph()
+# print(str(len(g.vertices)))
+a = Vertex('A')
+g.add_vertex(a)
+g.add_vertex(Vertex('B'))
+for i in range(ord('A'), ord('K')):
+	g.add_vertex(Vertex(chr(i)))
+
+edges = ['AB', 'AE', 'BF', 'CG', 'DE', 'DH', 'EH', 'FG', 'FI', 'FJ', 'GJ', 'HI']
+for edge in edges:
+	g.add_edge(edge[:1], edge[1:])
+
+g.print_graph()