Binary Tree Paths

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> result;    vector<string> binaryTreePaths(TreeNode* root) {                if(root == NULL)            return result;        getPath(root,to_string(root->val));        return result;    }        void getPath(TreeNode* root,string path){        if(root->left == NULL && root->right == NULL){            result.push_back(path);        }        if(root->left != NULL)            getPath(root->left,path+"->"+to_string(root->left->val));        if(root->right != NULL)            getPath(root->right,path+"->"+to_string(root->right->val));    }};