/*Given a binary tree, return all root-to-leaf paths.

For example, given the following binary tree:

1

/ \

2 3

\

5

All root-to-leaf paths are:

["1->2->5", "1->3"]

*/

/**

* 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:

vector<string> binaryTreePaths(TreeNode* root) {

if(root == NULL) return result;

binaryTreePaths_helper(root, "");

return result;

}

void binaryTreePaths_helper(TreeNode* root, string ans)

{

if(root == NULL) return;

if(root->left == NULL && root->right == NULL)

{

ans = ans + to_string(root->val);

result.push_back(ans);

}

else

ans = ans + to_string(root->val) + "->";

binaryTreePaths_helper(root->left, ans);

binaryTreePaths_helper(root->right, ans);

}

private:

vector<string> result;

};