2023-01-09 解題區►Leetcode►Easy Leetcode 144 - Binary Tree Preorder Traversal 題目 Problem# Binary Tree Traversal (pre-order) 想法# DFS 時間複雜度: $\mathcal{O}(V+E)$ 空間複雜度: $\mathcal{O}(V)$ AC Code# Newer Leetcode 1061 - Lexicographically Smallest Equivalent String Older Leetcode 134 - Gas Station