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.
1->3 represents the number 13. Return the sum = 12 + 13 = 25.
针对每一个结点, 都把它当作叶子来处理, 这样, 每个结点都会有个值, 其值的大小是父结点的值*１０, 返回值就加上自己的结点
/** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public: int vers(TreeNode *root, int path) { if(NULL==root)return 0; if(NULL==root->left&&NULL==root->right) return path * 10 + root->val; return vers(root->left, path * 10 + root->val) + vers(root->right, path * 10 + root->val); } int sumNumbers(TreeNode *root) { int path = 0; return vers(root, path); }};