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 / / 11 13 4 / / 7 2 5 1
return
[ [5,4,11,2], [5,8,4,5] ]
Code:
/** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: void findPath(TreeNode *node, int n, int &sum, vector<int> &buf, vector<vector<int>> &res){ if(!node) return; buf.push_back(node->val); if(!node->left&&!node->right&&node->val+n==sum){ res.push_back(buf); buf.pop_back(); return; } findPath(node->left,node->val+n,sum,buf,res); findPath(node->right,node->val+n,sum,buf,res); buf.pop_back(); } vector<vector<int> > pathSum(TreeNode *root, int sum) { vector<int> buf; vector<vector<int>> res; findPath(root,0,sum,buf,res); return res; } };