root.right =newTreeNode(6); root.right.left =newTreeNode(5); root.right.right =newTreeNode(7); root.right.right.right =newTreeNode(8); System.out.println(Main28.preorderTraversal(root)); } publicstaticclassTreeNode { intval; TreeNode left; TreeNode right; TreeNode(intx) { val = ...
TreeNode(intx) { val = x; } } 第一种方法:算法实现类 importjava.util.LinkedList;importjava.util.List;publicclassSolution{privateList<Integer> result;publicList<Integer>preorderTraversal(TreeNode root){ result =newLinkedList<>(); preOrder(root);returnresult; }privatevoidpreOrder(TreeNode root)...
Preorder Traversal: Sample Solution: Java Code: classNode{intkey;Nodeleft,right;publicNode(intitem){// Constructor to create a new Node with the given itemkey=item;left=right=null;}}classBinaryTree{Noderoot;BinaryTree(){// Constructor to create an empty binary treeroot=null;}voidprint_Preo...
代码: packagecom.niuke.p7;importjava.util.ArrayList;importjava.util.Stack;publicclassSolution {publicArrayList<Integer>preorderTraversal (TreeNode root) {//write code hereArrayList<Integer> list =newArrayList<>();if(root ==null) {returnlist; } Stack<TreeNode> stack =newStack<>(); stack.push(...
public List<Integer> preorderTraversal(TreeNode root) { List<Integer> list = new ArrayList<>(); preorderTraversalHelper(root, list); return list; } private void preorderTraversalHelper(TreeNode root, List<Integer> list) { if (root == null) { return; } list.add(root.val); preorderTrav...
Given preorder and inorder traversal of a tree, construct the binary tree. 二分法 复杂度 时间O(N^2) 空间 O(N) 思路 我们先考察先序遍历序列和中序遍历序列的特点。对于先序遍历序列,根在最前面,后面部分存在一个分割点,前半部分是根的左子树,后半部分是根的右子树。对于中序遍历序列,根在中间部分...
17 preorderTraversal(root->right); 18 return v; 19 } 20 vector<int> v; 21 }; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 非递归 1 /** 2 * Definition for binary tree
5. Construct Binary Tree from Preorder and Inorder Traversal 与上题类似,我们知道preorder第一个元素一定是根节点,按照这个特性可以找出根节点在inorder中的位置,从该位置分开,左右两边分别就是左右子树。 class Solution: def buildTree(self, preorder: List[int], inorder: List[int]) -> TreeNode: if...
The inOrder traversal is one of the most popular ways to traverse a binary tree data structure in Java. TheinOrdertraversal is one of the three most popular ways to traverse a binary tree data structure, the other two being thepreOrderandpostOrder. During the in-order traversal algorithm, ...
importjava.util.ArrayList;importjava.util.List;/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */publicclassSolution{public List<Integer>preorderTraversal(TreeNode root){ArrayList...