标签：style blog color 使用 io for ar div
Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number.
An example is the root-to-leaf path 1->2->3 which represents the number 123.
Find the total sum of all root-to-leaf numbers.
For example,
1
/ 2 3
The root-to-leaf path 1->2 represents the number 12.
The root-to-leaf path 1->3 represents the number 13.
Return the sum = 12 + 13 = 25.
思路：本题本质上是要对二叉树进行遍历。我们使用递归对二叉树进行深度优先遍历。
1 class Solution { 2 public: 3 int sumNumbers( TreeNode *root ) { 4 if( !root ) { return 0; } 5 return sumSub( root, 0 ); 6 } 7 private: 8 int sumSub( TreeNode *node, int num ) { 9 num = 10*num + node->val; 10 if( !node->left && !node->right ) { return num; } 11 int left = 0, right = 0; 12 if( node->left ) { left = sumSub( node->left, num ); } 13 if( node->right ) { right = sumSub( node->right, num ); } 14 return left + right; 15 } 16 };
Sum Root to Leaf Numbers,布布扣,bubuko.com
标签：style blog color 使用 io for ar div
原文地址：http://www.cnblogs.com/moderate-fish/p/3910351.html
