#Leet Code# Root to leaf

语言：Python

描述：使用递归实现

 1     def getList(self, node):
 2         if node is None:
 3             return []
 4
 5         if node.left is None and node.right is None:
 6             return [[node.val]]
 7
 8         result = []
 9         for item in self.getList(node.left):
10             result.append([node.val] + item)
11
12         for item in self.getList(node.right):
13             result.append([node.val] + item)
14
15         return result
16
17     def getNumByList(self, lst):
18         result = 0
19         for item in lst:
20             result *= 10
21             result += item
22         return result
23
24     def sumNumbers(self, root):
25         result = self.getList(root)
26         sum = 0
27         for item in result:
28             sum += self.getNumByList(item)
29         return sum

新的实现

 1 class Solution:
 2     # @param root, a tree node
 3     # @return an integer
 4     def sumPath(self, node, value):
 5         if node is None:
 6             return 0
 7
 8         value = value * 10 + node.val
 9         if (node.left is None and node.right is None):
10             self.sum += value
11
12         self.sumPath(node.left, value)
13         self.sumPath(node.right, value)
14
15     def sumNumbers(self, root):
16         self.sum = 0
17         self.sumPath(root, 0)
18
19         return self.sum   

#Leet Code# Root to leaf