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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>
69 lines
1.7 KiB
Python
69 lines
1.7 KiB
Python
"""
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File: recursion.py
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Created Time: 2023-08-24
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Author: krahets (krahets@163.com)
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"""
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def recur(n: int) -> int:
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"""再帰"""
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# 終了条件
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if n == 1:
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return 1
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# 再帰：再帰呼び出し
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res = recur(n - 1)
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# 復帰：結果を返す
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return n + res
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def for_loop_recur(n: int) -> int:
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"""反復で再帰をシミュレート"""
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# 明示的なスタックを使用してシステムコールスタックをシミュレート
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stack = []
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res = 0
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# 再帰：再帰呼び出し
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for i in range(n, 0, -1):
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# 「スタックへのプッシュ」で「再帰」をシミュレート
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stack.append(i)
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# 復帰：結果を返す
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while stack:
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# 「スタックからのポップ」で「復帰」をシミュレート
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res += stack.pop()
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# res = 1+2+3+...+n
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return res
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def tail_recur(n, res):
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"""末尾再帰"""
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# 終了条件
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if n == 0:
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return res
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# 末尾再帰呼び出し
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return tail_recur(n - 1, res + n)
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def fib(n: int) -> int:
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"""フィボナッチ数列：再帰"""
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# 終了条件 f(1) = 0, f(2) = 1
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if n == 1 or n == 2:
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return n - 1
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# 再帰呼び出し f(n) = f(n-1) + f(n-2)
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res = fib(n - 1) + fib(n - 2)
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# 結果 f(n) を返す
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return res
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"""Driver Code"""
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if __name__ == "__main__":
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n = 5
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res = recur(n)
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print(f"\n再帰関数の合計結果 res = {res}")
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res = for_loop_recur(n)
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print(f"\n反復で再帰をシミュレートする合計結果 res = {res}")
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res = tail_recur(n, 0)
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print(f"\n末尾再帰関数の合計結果 res = {res}")
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res = fib(n)
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print(f"\nフィボナッチ数列の第 {n} 項は {res} です") |