Leetcode 257.二叉树的所有路径

class Solution { public: vector<string> binaryTreePaths(TreeNode* root) { vector<string> paths; // result if (root == nullptr) { return paths; } queue<TreeNode*> node_queue; queue<string> path_queue; // bfs while (!node_queue.empty()) { TreeNode* node = node_queue.front(); string path = path_queue.front(); node_queue.pop(); path_queue.pop(); if (node->left == nullptr && node->right == nullptr) { paths.push_back(path); } else { if (node->left != nullptr) { node_queue.push(node->left); path_queue.push(path + "->" + to_string(node->left->val)); } if (node->right != nullptr) { node_queue.push(node->right); path_queue.push(path + "->" + tostring(node->right->val)); } } } return paths; } };