113. Path Sum II (Tree; DFS)

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 sum = 22 and,

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

Return

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

structTreeNode {intVal; TreeNode*Left ; TreeNode*Right ; TreeNode (intx): Val (x), left (null), right (null) {}};classSolution { Public: Vector<vector<int>> pathsum (TreeNode *root,intsum)        {pathgroup.clear (); if(!root)returnPathgroup; Target=sum; Vector<int>path; Preorder (Root,0, path); returnPathgroup; }    voidPreorder (treenode* node,intsum,vector<int>path) {Sum= Node->val +sum; Path.push_back (Node-val); if(node->Left ) {Preorder (node-Left,sum,path); }               if(node->Right ) {Preorder (node-Right,sum,path); }                if(!node->left &&!node->Right ) {            if(sum==target)            {pathgroup.push_back (path); }                }    }Private:    intTarget; Vector<vector<int>>Pathgroup;};

113. Path Sum II (Tree; DFS)