Preorder
144. Binary Tree Preorder Traversal
Solution 1://非递归 public List<Integer> preorderTraversal(TreeNode root) { List<Integer> result = new ArrayList<>(); if (root == null) { return result; ......
Binary Tree Preorder Traversal
Source Given a binary tree, return the preorder traversal of its nodes' values. Note Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,2,3]. Example Ch ......