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] ]
» Solve this problem
/**
* Definition for binary tree
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
private:
void traversal(TreeNode *root, int sum, int cur, vector<vector<int> > &answer, vector<int> &temp) {
temp.push_back(root->val);
if (root->left == NULL && root->right == NULL) {
if (root->val + cur == sum) {
answer.push_back(temp);
}
}
else {
if (root->left != NULL) {
traversal(root->left, sum, root->val + cur, answer, temp);
}
if (root->right != NULL) {
traversal(root->right, sum, root->val + cur, answer, temp);
}
}
temp.pop_back();
}
public:
vector<vector<int> > pathSum(TreeNode *root, int sum) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
vector<vector<int> > answer;
vector<int> temp;
if (root != NULL) {
traversal(root, sum, 0, answer, temp);
}
return answer;
}
};