G = nx.Graph()
positions = {}
coordinates = [
    [0, 4],
    [-4, 3],
    [4, 3],
    [-6, 2],
    [-2, 2],
    [2, 2],
    [6, 2],
    [-7, 1],
    [-5, 1],
    [-3, 1],
    [-1, 1],
    [1, 1],
    [3, 1],
    [5, 1],
    [7, 1],
    [4, 0],
    [6, 0],
    [8, 0]
]
parents = [0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 13, 14, 14]
for index in range(len(parents)):
    G.add_node(index)
    G.add_edge(index, parents[index])
    positions[index] = coordinates[index]
nx.draw(G, positions, node_size = 1000)
labels = {
    0: '0',
    1: '1',
    2: '2',
    3: '3',
    4: '4',
    5: '5',
    6: '6',
    7: 'tx1',
    8: 'tx2',
    9: 'tx3',
    10: 'tx4',
    11: 'tx5',
    12: 'tx6',
    13: '13',
    14: '14',
    15: 'tx7',
    16: 'tx8',
    17: 'tx9'
}
nx.draw_networkx_labels(G, positions, labels = labels)