[Leetcode] Path Sum II

Given a binary tree and a sum, find all root-to-leaf paths where each path ' s sum equals the Given sum.

For example:
Given the below binary tree and sum = 22,

              5             /             4   8           /   /           /  4         /  \    /         7 2 5   1

Return

[   [5,4,11,2],   [5,8,4,5]]

Hide TagsTree Depth-first Search

Idea: DFS, recursion, pay attention to the marked RED statement

/** Definition for binary tree * struct TreeNode {* int val; * TreeNode *left; * TreeNode *right; * TreeNode (int x): Val (x), left (null), right (NULL) {} *}; */classSolution {Vector<vector<int> >M_res; Vector<int>M_vec;  Public:        voidDFS (TreeNode * root,intsum) {            if(Root = =NULL)return; if(Root->left = = NULL && Root->right = =NULL) {                   if(Root->val = =sum) {M_vec.push_back (Root-val);                    M_res.push_back (M_vec);                M_vec.pop_back (); }                   return; } M_vec.push_back (Root ->val); if(root->Left ) {DFS (Root->left, sum-root->val); }               if(root->Right ) {DFS (Root->right, sum-root->val);        } M_vec.pop_back (); } Vector<vector<int> > Pathsum (TreeNode *root,intsum)            {m_vec.clear ();            M_res.clear ();            DFS (root, sum); returnM_res; }};

[Leetcode] Path Sum II