113 lines
3.1 KiB
Python
113 lines
3.1 KiB
Python
import random
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def generate_tree_from_prufer_code(code):
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L1 = {}
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L2 = []
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edges = []
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for node in range(len(code)+2):
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L2.append(node+1)
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for node in L2:
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L1[node] = 0
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for node in code:
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L1[node] += 1
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for k in range(len(L1)):
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current_node = L2[0]
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counter = 1
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if len(L2) > 2:
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while L1[current_node] > 0:
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current_node = L2[counter]
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counter += 1
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if code[k] < current_node:
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edges.append([code[k], current_node])
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else:
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edges.append([current_node, code[k]])
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L1[code[k]] -= 1
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L2.remove(current_node)
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edges.append([L2[0], L2[1]])
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return edges
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def generate_prufers_code(n: int):
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code = []
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for i in range(n-2):
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code.append(random.randint(1, n))
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return code
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def generate_random_graph(n: int, log=False):
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code = generate_prufers_code(n)
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edges = generate_tree_from_prufer_code(code)
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number_of_edges_to_add = random.randint(n//4, int(n/3))
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if log:
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print("number of edges to add:", number_of_edges_to_add)
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counter = 0
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while counter < number_of_edges_to_add:
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node1 = random.randint(1, n)
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node2 = random.randint(1, n)
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while node1 == node2:
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node2 = random.randint(1, n)
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if node1 < node2:
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if [node1, node2] not in edges:
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edges.append([node1, node2])
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counter += 1
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else:
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if [node2, node1] not in edges:
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edges.append([node2, node1])
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counter += 1
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return edges
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def write_graph_to_file(graph, filename, path="graphs/"):
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print("writing to file")
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with open(path + filename, 'w') as file:
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for edge in graph:
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weight = random.randint(1, 100)
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file.write(str(edge[0]) + " " + str(edge[1]) + " " + str(weight) + "\n")
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file.write(str(edge[1]) + " " + str(edge[0]) + " " + str(weight) + "\n")
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def read_graph_from_file(filename, path="graphs/"):
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N = set()
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A = {}
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A_b = {}
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w = {}
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with open(path + filename, 'r') as file:
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line = file.readline()
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while line != '':
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split = line.strip('\n').split(" ")
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first_node = int(split[0])
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second_node = int(split[1])
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N.add(first_node)
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N.add(second_node)
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if first_node not in A.keys():
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A[first_node] = [second_node]
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else:
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A[first_node].append(second_node)
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if second_node not in A_b.keys():
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A_b[second_node] = [first_node]
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else:
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A_b[second_node].append(first_node)
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w[(first_node, second_node)] = int(split[2])
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line = file.readline()
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return N, A, A_b, w
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if __name__ == '__main__':
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n = [100, 500, 1_000, 2_500, 5_000, 10_000, 25_000, 50_000, 100_000, 200_000]
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for i in range(1, 11):
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print("generating graph:", i, "of", 10, "with", n[i-1], "nodes")
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g = generate_random_graph(n[i-1], log=True)
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f = "graph" + str(i)
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write_graph_to_file(g, f)
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print()
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