标签：style blog class code java color
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.
这道题就很简单了。反正就是递归，每遍历到一个点，就把前面计算到的数*10+当前数，到叶子结点的时候就把数加一下。
叶子结点就是左右结点都为NULL。
1 /** 2 * Definition for binary tree 3 * struct TreeNode { 4 * int val; 5 * TreeNode *left; 6 * TreeNode *right; 7 * TreeNode(int x) : val(x), left(NULL), right(NULL) {} 8 * }; 9 */ 10 class Solution { 11 public: 12 int sumNumbers(TreeNode *root) { 13 int sum = 0; 14 recursive(root, 0, sum); 15 return sum; 16 } 17 18 void recursive(TreeNode* root, int value, int& sum) { 19 if (root == NULL) { 20 return; 21 } 22 int v = value * 10 + root->val; 23 if (root->left == NULL && root->right == NULL) { 24 sum += v; 25 } 26 recursive(root->left, v, sum); 27 recursive(root->right, v, sum); 28 } 29 };
Leetcode | Sum Root to Leaf Numbers,布布扣,bubuko.com
Leetcode | Sum Root to Leaf Numbers
标签：style blog class code java color
原文地址：http://www.cnblogs.com/linyx/p/3704449.html
