129. Sum Root to Leaf Numbers
题目:
https://leetcode.com/problems/sum-root-to-leaf-numbers/
难度:
Medium
其实递归不难想到，不过我自己做错在细节方面
如果只有单支，每朝下走一层，代表的数字都增加10， 10* 原本的 + 新节点的数字，最终也是用这个来解
class Solution(object):
def sumNumbers(self, root):
"""
:type root: TreeNode
:rtype: int
"""
return self.calSum(root,0)
def calSum(self,root,curSum):
if root == None:
return 0
else:
curSum = curSum * 10 + root.val
if root.left == None and root.right == None:
return curSum
else:
return self.calSum(root.left, curSum) + self.calSum(root.right, curSum)
