Given a binary tree, return all root-to-leaf paths.
Note: A leaf is a node with no children.
Example:
Input: 1 / 2 3 5 Output: ["1->2->5", "1->3"] Explanation: 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) { vector<string> res; if (!root) return res; binaryTreePaths(res, root, to_string(root->val)); return res; } void binaryTreePaths(vector<string>& res, TreeNode* root, string t) { if (!root->left && !root->right) { res.push_back(t); return; } if (root->left) binaryTreePaths(res, root->left, t + "->" + to_string(root->left->val)); if (root->right) binaryTreePaths(res, root->right, t + "->" + to_string(root->right->val)); } };