def test_tree_with_many_items(self):
preorder = ["a", "i", "x", "f", "r"]
inorder = ["i", "a", "f", "x", "r"]
expected = {
"v": "a",
"l": {
"v": "i",
"l": {},
"r": {}
},
"r": {
"v": "x",
"l": {
"v": "f",
"l": {},
"r": {}
},
"r": {
"v": "r",
"l": {},
"r": {}
}
}
}
self.assertEqual(tree_from_traversals(preorder, inorder), expected)
def test_tree_with_one_item(self):
preorder = ["a"]
inorder = ["a"]
expected = {
"v": "a",
"l": {},
"r": {}
}
self.assertEqual(tree_from_traversals(preorder, inorder), expected)
def test_empty_tree(self):
preorder = []
inorder = []
expected = {}
self.assertEqual(tree_from_traversals(preorder, inorder), expected)
def test_reject_traverals_with_repeated_items(self):
preorder = ["a", "b", "a"]
inorder = ["b", "a", "a"]
with self.assertRaisesWithMessage(ValueError):
tree_from_traversals(preorder, inorder)
def test_reject_inconsistent_traversals_of_same_length(self):
preorder = ["x", "y", "z"]
inorder = ["a", "b", "c"]
with self.assertRaisesWithMessage(ValueError):
tree_from_traversals(preorder, inorder)
def test_reject_traverals_of_different_length(self):
preorder = ["a", "b"]
inorder = ["b", "a", "r"]
with self.assertRaisesWithMessage(ValueError):
tree_from_traversals(preorder, inorder)