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7257641e0e
* Retranslate the complete Japanese online edition from Chinese * Fit Japanese homepage labels and localize heading permalinks * Point Japanese contribution instructions to the Japanese preview * Replace locale conditionals with multilingual UI tables
45 lines
1.3 KiB
Python
45 lines
1.3 KiB
Python
"""
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File: permutations_i.py
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Created Time: 2023-04-15
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Author: krahets (krahets@163.com)
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"""
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def backtrack(
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state: list[int], choices: list[int], selected: list[bool], res: list[list[int]]
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):
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"""バックトラッキング：すべての順列 I"""
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# 状態の長さが要素数と等しくなったら、解を記録する
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if len(state) == len(choices):
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res.append(list(state))
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return
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# すべての選択肢を走査する
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for i, choice in enumerate(choices):
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# 枝刈り：同じ要素を繰り返し選んではならない
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if not selected[i]:
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# 試行：選択を行い、状態を更新する
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selected[i] = True
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state.append(choice)
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# 次の選択に進む
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backtrack(state, choices, selected, res)
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# 復元：選択を取り消し、以前の状態に戻す
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selected[i] = False
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state.pop()
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def permutations_i(nums: list[int]) -> list[list[int]]:
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"""すべての順列 I"""
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res = []
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backtrack(state=[], choices=nums, selected=[False] * len(nums), res=res)
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return res
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"""実行用コード"""
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if __name__ == "__main__":
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nums = [1, 2, 3]
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res = permutations_i(nums)
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print(f"入力配列 nums = {nums}")
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print(f"すべての順列 res = {res}")
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