def test_postfix_tokens(self):
tree = BinaryTree()
root = BinaryTreeNode('*')
tree.root = root
left = root.add_left('+')
right = root.add_right('+')
left.add_left('A')
left.add_right('B')
right.add_left('C')
right.add_right('D')
tokens = ['A', 'B', 'C', tree.root.label, '+', 'D', '+']
result = tree.postfix_tokens()
self.assertCountEqual(result, tokens)
tree = BinaryTree()
root = BinaryTreeNode('+')
tree.root = root
left = root.add_left('+')
right = root.add_right('+')
left.add_left('A')
left.add_right('B')
right.add_left('C')
right.add_right('D')
tokens = ['A', 'B', '+', 'C', '+', 'D', '+']
result = tree.postfix_tokens()
self.assertCountEqual(result, tokens)
def _mutate_subtree_exchange(
operators: list,
operands: list,
tree: BinaryTree,
tree_generator: BinaryTreeGenerator) -> BinaryTree:
"""Mutate sub-tree exchange.
:param tree:
:param tree_generator:
:return:
"""
postfix_tokens = tree.postfix_tokens()
random_tree = tree_generator.generate(operators, operands)
r = np.random.randint(0, len(postfix_tokens))
new_tree = SubTreeExchangeMutator._swap_mut_subtree(tree, r, random_tree)
return new_tree