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トップ関数に関する質問再帰を用いた関数から返り値が返ってこない

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1

コード修正

2021/07/13 02:58

投稿

ozwk
ozwk

スコア13528

test CHANGED
@@ -54,17 +54,51 @@
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  ```python
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+ # coding: utf-8
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+
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+ # Your code here!
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+
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+
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+
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+ maze = [
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+
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+ [9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9],
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+
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+ [9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 9],
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+
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+ [9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 0, 9],
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+
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+ [9, 9, 0, 0, 0, 0, 0, 0, 0, 9, 0, 9],
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+
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+ [9, 9, 0, 0, 9, 9, 9, 9, 0, 9, 0, 9],
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+
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+ [9, 9, 9, 0, 0, 0, 0, 9, 0, 9, 0, 9],
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+
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+ [9, 9, 9, 9, 9, 9, 0, 9, 0, 9, 0, 9],
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+
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+ [9, 1, 0, 9, 0, 9, 0, 9, 0, 9, 0, 9],
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+
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+ [9, 9, 0, 9, 0, 9, 0, 9, 0, 9, 0, 9],
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+
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+ [9, 9, 0, 9, 0, 9, 0, 9, 0, 9, 0, 9],
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+
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+ [9, 9, 0, 0, 0, 0, 0, 9, 0, 0, 0, 9],
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+
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+ [9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9]
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+
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+ ]
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+
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+
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+
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+
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+
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  def dfs(x, y, d):
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  if maze[x][y] == 1:
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- print(d)
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-
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  return d
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- #exit()
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+
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-
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-
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  maze[x][y] = 2
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@@ -72,22 +106,52 @@
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  if maze[x - 1][y] < 2:
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- return dfs(x - 1, y, d + 1)
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+ r = dfs(x - 1, y, d + 1)
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+
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+ if r is not None:
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+
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+ return r
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+
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+
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  if maze[x + 1][y] < 2:
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- return dfs(x + 1, y, d + 1)
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+ r = dfs(x + 1, y, d + 1)
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+
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+ if r is not None:
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+
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+ return r
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+
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+
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  if maze[x][y - 1] < 2:
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- return dfs(x, y - 1, d + 1)
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+ r = dfs(x, y - 1, d + 1)
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+
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+ if r is not None:
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+
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+ return r
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+
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+
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  if maze[x][y + 1] < 2:
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- return dfs(x, y + 1, d + 1)
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+ r = dfs(x, y + 1, d + 1)
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+
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+ if r is not None:
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+
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+ return r
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  maze[x][y] = 0
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+ return None
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+
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+
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+
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+
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+
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+ print(dfs(1, 1, 0))
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+
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  ```