#Leet Code# Root to leaf

语言：Python

描述：使用递归实现

    def getList(self, node):
        if node is None:
            return []

        if node.left is None and node.right is None:
            return [[node.val]]

        result = []
        for item in self.getList(node.left):
            result.append([node.val] + item) 

        for item in self.getList(node.right):
            result.append([node.val] + item) 

        return result

    def getNumByList(self, lst):
        result = 0
        for item in lst:
            result *= 10
            result += item
        return result

    def sumNumbers(self, root):
        result = self.getList(root)
        sum = 0
        for item in result:
            sum += self.getNumByList(item)
        return sum

新的实现

class Solution:
    # @param root, a tree node
    # @return an integer
    def sumPath(self, node, value):
        if node is None:
            return 0

        value = value * 10 + node.val
        if (node.left is None and node.right is None):
            self.sum += value
         
        self.sumPath(node.left, value)
        self.sumPath(node.right, value)

    def sumNumbers(self, root):
        self.sum = 0
        self.sumPath(root, 0)

        return self.sum