ravl: add ravl tree

Signed-off-by: Matej Focko <mfocko@redhat.com>
This commit is contained in:
Matej Focko 2022-01-30 15:03:59 +01:00
parent 4a832e1de8
commit 518ee5b970
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2 changed files with 167 additions and 0 deletions

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ravl.py Normal file
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from wavl import WAVLTree
from node import Node, Comparable
import logging
from typing import TypeVar, Optional
logger = logging.getLogger(__name__)
T = TypeVar("T", bound=Comparable)
class RAVLTree(WAVLTree[T]):
def is_correct_node(
self, node: Optional[Node[T]], recursive: bool = True
) -> bool:
if not node:
return True
if not all(child_rank > 0 for child_rank in Node.differences(node)):
return False
return not recursive or (
self.is_correct_node(node.left)
and self.is_correct_node(node.right)
)
# region DeleteRebalance
def _delete_rebalance(
self, node: Optional[Node[T]], parent: Optional[Node[T]]
) -> None:
# There is no rebalance after delete in rAVL tree
pass
# endregion DeleteRebalance

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test_ravl.py Normal file
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from ravl import RAVLTree
import hypothesis
import hypothesis.strategies as st
import logging
import pytest
import random
logger = logging.getLogger(__name__)
def test_empty():
tree = RAVLTree()
assert tree.root is None
assert tree.is_correct
def test_one_node():
tree = RAVLTree()
tree.insert(1)
assert tree.root is not None
assert 1 == tree.root.value
assert 0 == tree.root.rank
assert tree.root.left is None
assert tree.root.right is None
assert tree.is_correct
@pytest.mark.parametrize("values", [[1, 2], [1, 2, 0]])
def test_no_rebalance_needed(values):
tree = RAVLTree()
for value in values:
tree.insert(value)
assert tree.is_correct
def test_three_nodes_rebalanced():
tree = RAVLTree()
for value in (1, 2, 3):
print(tree)
tree.insert(value)
assert tree.is_correct
def test_bigger_tree():
tree = RAVLTree()
for i in range(50):
tree.insert(i)
assert tree.is_correct
def test_bigger_tree_reversed():
tree = RAVLTree()
for i in range(50):
tree.insert(-i)
assert tree.is_correct
def test_promote():
tree = RAVLTree()
for value in (0, 1, -1):
tree.insert(value)
assert tree.is_correct
@pytest.mark.parametrize(
"values",
[
[0, 1, -2, -1, -3],
[0, 1, -2, -1, -3, -4, 4, 9, 7],
[0, 1, -2, -1, -3, -4, 4, 9, 7, 5, -5, 8],
],
)
def test_rotate(values):
tree = RAVLTree()
for value in values:
tree.insert(value)
assert tree.is_correct
@hypothesis.settings(max_examples=1000, deadline=None)
@hypothesis.given(values=st.sets(st.integers()))
def test_insert_random(values):
tree = RAVLTree()
for value in values:
tree.insert(value)
assert tree.is_correct
assert tree.search(value) is not None
@st.composite
def delete_strategy(draw):
values = list(draw(st.sets(st.integers())))
delete_order = values.copy()
random.shuffle(delete_order)
return (values, delete_order)
@hypothesis.settings(max_examples=10000, deadline=None)
@hypothesis.given(config=delete_strategy())
def test_delete_random(config):
values, delete_order = config
tree = RAVLTree()
for value in values:
tree.insert(value)
for value in delete_order:
before = str(tree)
tree.delete(value)
after = str(tree)
try:
assert tree.is_correct
except AssertionError:
logger.info(
f"[FAIL] Delete {value} from {values} in order {delete_order}"
)
logger.info(f"Before:\n{before}")
logger.info(f"After:\n{after}")
raise