[Leetcode] Sum Root to Leaf Numbers

Given a binary tree containing digits from only 0-9 , 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 = + = 25 .

Hide TagsTree Depth-first Search

Idea: Typical DFS deep search

/** Definition for binary tree * struct TreeNode {* int val; * TreeNode *left; * TreeNode *right; * T Reenode (int x): Val (x), left (null), right (NULL) {} *}; */classSolution {Private:        intm_sum; Vector<int>M_vec; intIntvec2int (vector<int>nums) {            intnum =0;  for(inti =0; I < nums.size (); i++) {num= num *Ten+Nums[i]; }            returnnum; }        voidDFS (treenode*root) {            if(Root = =NULL)return; M_vec.push_back (Root-val); if(Root->left = = NULL && Root->right = =NULL) {M_sum+=Intvec2int (M_vec);                M_vec.pop_back (); return; }            if(root->Left ) Dfs (root-Left ); if(root->Right ) Dfs (root-Right );        M_vec.pop_back (); }     Public:        intSumnumbers (TreeNode *root)            {m_vec.clear (); M_sum=0;            DFS (root); returnm_sum; }};

[Leetcode] Sum Root to Leaf Numbers