标签：
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.
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分析：
前序式深度优先即可！
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
int sumNumbers(TreeNode* root) {
if(root==NULL)//叶子
return 0;
m_sum=0;
helpSum(root,root->val);
return m_sum;
}
void helpSum(TreeNode* node,int curVal) {
if(node->left==NULL && node->right==NULL)//叶子即可得到当前和
{
m_sum+=curVal;
return;
}
if(node->left!=NULL)
helpSum(node->left,10*curVal+node->left->val);
if(node->right!=NULL)
helpSum(node->right,10*curVal+node->right->val);
}
private:
int m_sum;
};
注：本博文为EbowTang原创，后续可能继续更新本文。如果转载，请务必复制本条信息！
原文地址：http://blog.csdn.net/ebowtang/article/details/51232508
原作者博客：http://blog.csdn.net/ebowtang
本博客LeetCode题解索引：http://blog.csdn.net/ebowtang/article/details/50668895
<LeetCode OJ> 129. Sum Root to Leaf Numbers
标签：
原文地址：http://blog.csdn.net/ebowtang/article/details/51232508
