题解 | #二叉树根节点到叶子节点的所有路径和#

'''
解题思路：
1、先dfs搜索，返回节点路径
2、当前为末端节点，全局保存
3、数据与字符转换操作
'''
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

#
# 
# @param root TreeNode类 
# @return int整型
#
class Solution:
    def sumNumbers(self , root ):
        # write code here

        if not root:
            return 0

        res = [root.val]
        out = []
        def dfs(root,res):
            if not root.left and not root.right:
                out.append(res)
            if root.left:
                dfs(root.left,res+[root.left.val])
            if root.right:
                dfs(root.right,res+[root.right.val])

        dfs(root,res)
        #print(out)

        s = 0
        for t in out:
            a = int(''.join(map(str,t)))
            #print(a)
            s += a

        return s

'''
root = TreeNode(1)
root.left = TreeNode(2)
root.right = TreeNode(3)
root.left.left = TreeNode(4)
root.left.right = TreeNode(5)
root.right.left = TreeNode(6)
root.right.right = TreeNode(7)
print(Solution().sumNumbers(root))
'''