Leetcode 257. Binary Tree Paths (Easy) (cpp)

Leetcode 257. Binary Tree Paths (Easy) (cpp)

Tag: Tree, Depth-first Search

Difficulty: Easy

/*257. Binary Tree Paths (Easy)Given a binary tree, return all root-to-leaf paths.For example, given the following binary tree:   1 /   \2     3 \  5All 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; else if (!(root -> left) && !(root -> right)) res.push_back(to_string(root -> val)); string head = to_string(root->val) + "->"; for(auto item: binaryTreePaths(root->left)) res.push_back(head + item); for(auto item: binaryTreePaths(root->right)) res.push_back(head + item); return res; } };