1classSolution {2public:3vector<int> postorderTraversal(TreeNode *root) {4vector<int>result;5stack<TreeNode *>s;6TreeNode *p =root;7TreeNode *q = nullptr, *last =nullptr;8while(!s.empty() ||p) {9if(p) {10s.push(p);11p = p->left;12}else{13q =s.top();14if(q->right &...
二叉树遍历(Binary Tree Traversal) 二叉树的递归遍历比较简单,这里说一下非递归遍历,以中序遍历为例子。 非递归遍历主要用到栈来协助进行。对于一个二叉树,首先根节点入栈,如果有左儿子,则继续入栈,重复直到最左边的儿子,这时候此节点值为要遍历的第一个值,他父亲是在栈顶。所以我们做一次出栈操作 f = stack...
Implementation of Inorder, Preorder, and Postorder traversal or a binary tree / binary search tree. Learn to implement binary tree traversal methods: Inorder, Preorder, and Postorder. Code examples are provided for traversing nodes in specific orders in
Postorder Traversal 首先是recursion写法,相对简单: // left->right->rootpublicList<Integer>preorderTraversal(TreeNoderoot){List<Integer>res=newArrayList<>();if(root==null){returnres;}res.addAll(inorderTraversal(root.left));res.addAll(inorderTraversal(root.left));res.add(root.val);} 如果用iter...
*/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...
二叉树的中序遍历。 解法一 递归 学二叉树的时候,必学的算法。用递归写简洁明了,就不多说了。 publicList<Integer>inorderTraversal(TreeNoderoot){List<Integer>ans=newArrayList<>();getAns(root,ans);returnans;}privatevoidgetAns(TreeNodenode,List<Integer>ans){if(node==null){return;}getAns(node.lef...
Tree traversal is the process of visiting each node in the tree exactly once. Visiting each node in a graph should be done in a systematic manner. If search result in a visit to all the vertices, it is called a traversal. There are basically three traversal techniques for a binary tree ...
Leetcode 94 binary tree inorder traversal 思路是从根节点开始,先将根节点压入栈,然后再将其所有左子结点压入栈,然后取出栈顶节点,保存节点值,再将当前指针移到其右子节点上,若存在右子节点,则在下次循环时又可将其所有左子结点压入栈中。这样就保证了访问顺序为左-根-右。
本题也属于层次遍历的变形,不同之处在于其遍历的方法是交替进行的,形成一个ZigZag的曲线形式,如下:代码如下: 1 struct TreeNode { 2 int
In this article, we will discuss 3 different techniques for Level Order Traversal of a binary tree. This technique can be used to find the left and right view of the tree.