Sum Root to Leaf Numbers

LeetCode Sum Root to Leaf Numbers

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.

深度优先搜索：

//将动态数组中的单个数数转换成整数int vecToInt(vector<int>& v){int sum = 0;for(int i=0; i<v.size(); i++){sum += (pow(10, v.size()-1-i)*v[i]);}return sum;}void pathSum(TreeNode* p, vector<int>& sub_sum, int & sum){//如果是叶节点，则计算出动态数组中的数字，计入sum中if(p->left==NULL && p->right==NULL){sub_sum.push_back(p->val);sum = sum + vecToInt(sub_sum);return ;}sub_sum.push_back(p->val);if(p->left!=NULL){pathSum(p->left, sub_sum, sum);sub_sum.pop_back();}if(p->right!=NULL){pathSum(p->right, sub_sum, sum);sub_sum.pop_back();}}int sumNumbers(TreeNode *root) {if(root==NULL)return 0;vector<int> sub_sum;int sum = 0;pathSum(root, sub_sum, sum);return sum;}