[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
This commit is contained in:
pre-commit-ci[bot] 2025-01-13 22:08:27 +00:00
parent c8ac0429ec
commit a82ab09004

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@ -25,21 +25,21 @@ def swap(a: int, b: int) -> tuple[int, int]:
def create_sparse(max_node: int, parent: list[list[int]]) -> list[list[int]]:
"""
Create a sparse table that saves each node's 2^i-th parent.
The given ``parent`` table should have the direct parent of each node in row 0.
This function fills in:
parent[j][i] = parent[j - 1][parent[j - 1][i]]
for each j where 2^j is less than max_node.
For example, consider a small tree where:
- Node 1 is the root (its parent is 0),
- Nodes 2 and 3 have parent 1.
We set up the parent table for only two levels (row 0 and row 1)
for max_node = 3. (Note that in practice the table has many rows.)
>>> parent0 = [0, 0, 1, 1] # 0 is unused; node1's parent=0, nodes 2 and 3's parent=1.
>>> parent1 = [0, 0, 0, 0]
>>> parent = [parent0, parent1]
@ -61,11 +61,11 @@ def lowest_common_ancestor(
) -> int:
"""
Return the lowest common ancestor (LCA) of nodes u and v in a tree.
The lists ``level`` and ``parent`` must be precomputed. ``level[i]`` is the depth
of node i, and ``parent`` is a sparse table where parent[0][i] is the direct parent
of node i.
>>> # Consider a simple tree:
>>> # 1
>>> # / \\
@ -106,10 +106,10 @@ def breadth_first_search(
) -> tuple[list[int], list[list[int]]]:
"""
Run a breadth-first search (BFS) from the root node of the tree.
This sets each node's direct parent (stored in parent[0]) and calculates the
depth (level) of each node from the root.
>>> # Consider a simple tree:
>>> # 1
>>> # / \\
@ -140,17 +140,17 @@ def main() -> None:
"""
Run a BFS to set node depths and parents in a sample tree, then create the
sparse table and compute several lowest common ancestors.
The sample tree used is:
1
/ | \
/ | \
2 3 4
/ / \\ \\
5 6 7 8
/ \\ | / \\
9 10 11 12 13
The expected lowest common ancestors are:
- LCA(1, 3) --> 1
- LCA(5, 6) --> 1
@ -158,9 +158,9 @@ def main() -> None:
- LCA(6, 7) --> 3
- LCA(4, 12) --> 4
- LCA(8, 8) --> 8
To test main() without it printing to the console, we capture the output.
>>> import sys
>>> from io import StringIO
>>> backup = sys.stdout