mirror of
https://github.com/krahets/hello-algo.git
synced 2025-11-01 03:24:24 +08:00
954c45864b
* docs: add Japanese documents (`ja/docs`) * docs: add Japanese documents (`ja/codes`) * docs: add Japanese documents * Remove pythontutor blocks in ja/ * Add an empty at the end of each markdown file. * Add the missing figures (use the English version temporarily). * Add index.md for Japanese version. * Add index.html for Japanese version. * Add missing index.assets * Fix backtracking_algorithm.md for Japanese version. * Add avatar_eltociear.jpg. Fix image links on the Japanese landing page. * Add the Japanese banner. --------- Co-authored-by: krahets <krahets@163.com>
46 lines
1.5 KiB
Python
46 lines
1.5 KiB
Python
"""
|
|
File: permutations_ii.py
|
|
Created Time: 2023-04-15
|
|
Author: krahets (krahets@163.com)
|
|
"""
|
|
|
|
|
|
def backtrack(
|
|
state: list[int], choices: list[int], selected: list[bool], res: list[list[int]]
|
|
):
|
|
"""バックトラッキングアルゴリズム：順列 II"""
|
|
# 状態の長さが要素数と等しいとき、解を記録
|
|
if len(state) == len(choices):
|
|
res.append(list(state))
|
|
return
|
|
# すべての選択肢を走査
|
|
duplicated = set[int]()
|
|
for i, choice in enumerate(choices):
|
|
# 枝刈り：要素の重複選択を許可せず、等しい要素の重複選択も許可しない
|
|
if not selected[i] and choice not in duplicated:
|
|
# 試行：選択を行い、状態を更新
|
|
duplicated.add(choice) # 選択された要素値を記録
|
|
selected[i] = True
|
|
state.append(choice)
|
|
# 次の選択ラウンドに進む
|
|
backtrack(state, choices, selected, res)
|
|
# 撤回：選択を取り消し、前の状態に復元
|
|
selected[i] = False
|
|
state.pop()
|
|
|
|
|
|
def permutations_ii(nums: list[int]) -> list[list[int]]:
|
|
"""順列 II"""
|
|
res = []
|
|
backtrack(state=[], choices=nums, selected=[False] * len(nums), res=res)
|
|
return res
|
|
|
|
|
|
"""ドライバーコード"""
|
|
if __name__ == "__main__":
|
|
nums = [1, 2, 2]
|
|
|
|
res = permutations_ii(nums)
|
|
|
|
print(f"入力配列 nums = {nums}")
|
|
print(f"すべての順列 res = {res}") |