从inorder, preorder 中buildtree。 还有从preorder, postorder中buildtree。这三种方式都遵循着一个思想,就是他们是从recursion 建立的数组,那么inorder 就必须left root right, postorder 就必须left right root, 那么postorder最后一个就是root,你用这个反过来建立tree就可以了,用inorder 作为参考,因为inorder最后...
*/classSolution{public List<Integer>preorderTraversal(TreeNode root){List<Integer>result=newLinkedList<>();TreeNode current=root;TreeNode prev=null;while(current!=null){if(current.left==null){result.add(current.val);current=current.right;}else{// has left, then find the rightmost of left su...
前序Preorder: 先访问根节点,然后访问左子树,最后访问右子树。子树递归同理 中序Inorder: 先访问左子树,然后访问根节点,最后访问右子树. 后序Postorder:先访问左子树,然后访问右子树,最后访问根节点. classNode:def__init__(self,key):self.left=Noneself.right=Noneself.val=keydefprintInorder(root):ifroot...
65publicstaticvoidinOrder(TreeNode root){66if(root ==null)return;67inOrder(root.left);68visit(root);69inOrder(root.right);70}7172publicstaticvoidinOrder2(TreeNode root){73if(root ==null)return;74Stack<TreeNode> stack =newStack<TreeNode>();75while(!stack.empty() || root !=null){76...
confused what"{1,#,2,3}"means?> read more on how binary tree is serialized on OJ. 思路: preorder用栈两三下就写完了 1vector<int> preorderTraversal(TreeNode *root) {2vector<int>nodes;3if(root == NULL)returnnodes;4stack<TreeNode *>tStack;5tStack.push(root);6while(!tStack.empty()...
preorder_visit(node_a);//先序 Console.WriteLine(); inorder_visit(node_a);//中序 Console.WriteLine(); postorder_visit(node_a);//后序 Console.WriteLine(); node node_1 =newnode("1"); node node_2 =newnode("2"); node node_3 =newnode("3"); ...
Preorder, Inorder, and Postorder非递归总结 Preorder, Inorder, and Postorder Iteratively Summarization[1] 1.Pre Order Traverse 1publicList<Integer>preorderTraversal(TreeNode root) {2List<Integer> result =newArrayList<>();3Deque<TreeNode> stack =newArrayDeque<>();4TreeNode p =root;5while(!
preorder,inorder,postorder 前序遍历preorder:根左右 var preorder = function(root) { var res = []; helper(root,res); return res; }; var helper = function(root,res){ if(root){ res.push(root.val); //根 root.children.map(child=>helper(child,res)) //左右...
1、preorder + inorder 第一个版本,使用坐标范围: 1/**2* Definition for binary tree3* struct TreeNode {4* int val;5* TreeNode *left;6* TreeNode *right;7* TreeNode(int x) : val(x), left(NULL), right(NULL) {}8* };9*/10classSolution {11public:12TreeNode *build(vector<int> ...
1 preorder: 节点入栈一次, 入栈之前访问。 2 inorder:节点入栈一次,出栈之后访问。 3 postorder:节点入栈2次,第二次出战后访问。 1classSolution {2public:3vector<int> preorderTraversal(TreeNode *root) {45vector<int>result;6stack<TreeNode*>stack;78TreeNode *p =root;910while( NULL != p ||...