Code & Func

第89天。

Given a binary tree, return all root-to-leaf paths.

For example, given the following binary tree:

1 /
2 3
5

All root-to-leaf paths are:

[“1->2->5”, “1->3”]

比较的简单的题目，直接用递归做就好了，因为python写起来比较简单，所以这里用python实现：

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def binaryTreePaths(self, root):
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    """
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    :type root: TreeNode
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    :rtype: List[str]
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    """
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    self.ret = []
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    if root is None:
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        return self.ret
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    s = []
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    self.binaryTreePathsRec(root,s)
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    return self.ret
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def binaryTreePathsRec(self,root,s):
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    if root is None:
8 collapsed lines
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        return
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    s.append(str(root.val))
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    if root.left is None and root.right is None:
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        self.ret.append('->'.join(s))
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    else:
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        self.binaryTreePathsRec(root.left,s)
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        self.binaryTreePathsRec(root.right,s)
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    s.pop()