def random_graph(n, p, directed=False):
"""
Create a random graph
:param n: number of nodes
:param p: probability of edge creation (0 to 100)
:param directed: set to True to generate a directed graph. Default is False (undirected graph)
:return: graph
"""
if not directed:
g = Graph()
for i in range(n):
g.add_vertex(i)
for u, v in combinations(g.vertices, 2):
# print(u, v)
if randrange(1, 101) <= p:
g.add_edge(u, v)
return g
else:
dg = Digraph()
for i in range(n):
dg.add_vertex(i)
for u, v in permutations(dg.vertices, 2):
# print(u, v)
if randrange(1, 101) <= p:
dg.add_edge(u, v)
return dg
def transpose(g):
gt = Digraph()
for u in g.vertices:
gt.add_vertex(u)
for u, v in g.edges:
gt.add_edge(v, u, g.weight(u, v))
return gt
# curr = vertex
# while pred[curr] != source and pred[curr] is not None:
# dfs_path.appendleft(pred[curr])
# curr = pred[curr]
# if pred[curr] is None:
# dfs_path = []
# else:
# dfs_path.appendleft(pred[curr])
# # print('path from ' + source + ' to ' + vertex + ' ' + str(bfs_path))
# print(f'path from {source} to {vertex} : {str(list(dfs_path)):20} '
# f'discovery at {dtime[vertex]} finishing at {ftime[vertex]}')
# print('')
if __name__ == '__main__':
dg = Digraph()
dg.add_edge('u', 'v') # Cormen book example
dg.add_edge('u', 'x')
dg.add_edge('v', 'y')
dg.add_edge('w', 'y')
dg.add_edge('w', 'z')
dg.add_edge('x', 'v')
dg.add_edge('y', 'x')
dg.add_edge('z', 'z')
print('Digraph:', dg)
print('Vertices:', dg.vertices)
print('Edges:', dg.edges)
print('')
print('dfs print ', end='')
dfs_print_vertices(dg)
# n = len(g.vertices())
# edges = g.edges()
# t = [[[0] * n for _ in range(n)] for _ in range(n + 1)]
# for i in range(n):
# for j in range(n):
# if i == j or (i + 1, j + 1) in edges:
# t[0][i][j] = 1
# for k in range(1, n + 1):
# for i in range(n):
# for j in range(n):
# t[k][i][j] = t[k - 1][i][j] or (t[k - 1][i][k - 1] and t[k - 1][k - 1][j])
# return t
if __name__ == '__main__':
dg = Digraph()
dg.add_edge(2, 3)
dg.add_edge(2, 4)
dg.add_edge(3, 2)
dg.add_edge(4, 1)
dg.add_edge(4, 3)
print(dg)
print(dg.edges())
t = transitive_closure(dg)
# for i, tc in enumerate(t):
# print(f't[{i}]')
# for row in tc:
# print(row)
for row in t: