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]]
class Solution {
public:
vector<vector<int>> res;
void dfs(TreeNode* root,int sum,vector<int> v){
if(root==NULL) return;
v.push_back(root->val);
if(root->left==NULL&&root->right==NULL&&root->val==sum){
res.push_back(v);
return;
}
if(root->left){
dfs(root->left,sum-root->val,v);
}
if(root->right){
dfs(root->right,sum-root->val,v);
}
}
vector<vector<int>> pathSum(TreeNode* root, int sum) {
if(root==NULL) return res;
dfs(root,sum,vector<int> (0));
return res;
}
};
