/**

* Definition for a binary tree node.

* struct TreeNode {

* int val;

* TreeNode *left;

* TreeNode *right;

* TreeNode(int x) : val(x), left(NULL), right(NULL) {}

* };

*/

class Solution {

public:

void buildPath(TreeNode* root, vector<string>& res, string path)

{

if (!root) return;

path += "->";

path += to_string(root->val);

if (!root->left && !root->right) //leaf node

{

res.push_back(path);

return;

}

buildPath(root->left, res, path);

buildPath(root->right, res, path);

}

vector<string> binaryTreePaths(TreeNode* root) {

vector<string> res;

if (!root) return res;

string rootnode = to_string(root->val);

if (!root->left && !root->right)

{

res.push_back(rootnode);

return res;

}

buildPath(root->left, res, rootnode);

buildPath(root->right, res, rootnode);

return res;

}

};