###257. Binary Tree Paths

题目:

<https://leetcode.com/problems/binary-tree-paths/>


难度:

Easy


Tag ： tree， DFS

类似的题目是Path Sum Ⅱ


第一眼看起来不像easy题目,然后堵了一下自己写的Path Sum Ⅱ自己的解答

同一种花样

```
class Solution:
    # @param {TreeNode} root
    # @return {string[]}
    def binaryTreePaths(self, root):
        if root == None: return []
        result = []
        self.auxTreePaths(root,result,"")
        return result
        
    
    def auxTreePaths(self,root,result,curStr):
        if root == None:
            return
        curStr += str(root.val)
        if root.left == None and root.right == None:
            result.append(curStr)
        if root.left:
            self.auxTreePaths(root.left,result,curStr + "->")
        if root.right:
            self.auxTreePaths(root.right,result,curStr + "->")
        
```