tree node properties Node
- data: node value
- parent : points to the parent node of the node
- left: point to the left node of the node
- right: point to the right node of the node
When removing nodes, consider the following situations:
1: Remove suddenly the node does not exist
2: The root node is removed
3: The root node is not removed
3.1: If this node is larger than the root node, go to the right node of the root node to find
3.1.1 Whether the right node of the node exists or not
3.2: If this node is smaller than the root node, go to the left node of the root node to find
3.2.1 Whether the right node of the node exists or not
The last is to connect the smallest node of the child node of the deleted node to its left node
This is my personal solution to delete this node, if you have any better way, please advise! ! ! !
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
</body>
<script>
/*this.insert=insert//插入节点（insert node)
this.find=find//查找元素(find node in Binary tree)
this.getMin=getMin//查找最小值(get the min node in Binary tree)
this.getMax=getMax//查找最大值(get the max node in Binary tree)
this.remove =remove //移除节点(Remove node from binary tree)
this.InSort =InSort //中序遍历（In-order traversal）
this.PreSort =PreSort //前序遍历（Pre-order traversal）
this.PostSort=PostSort //后序遍历（post-order traversal）
*/
function Node(element,left,right,parent){
this.element=element;
this.left=left;
this.right=right;
this.parent=parent;
this.show=function () {
return this.element;
}
}
function BST() {
this.root=null;
//插入节点（insert node)
this.insert=function (element) {
var node=new Node(element,null,null);
if(this.root==null){
this.root=node;
}else{
var buffer=this.root;
var parent;
while(true){
parent=buffer;
if(element>buffer.element){
buffer=buffer.right;
if(buffer==null){
node.parent=parent;
parent.right=node;
break;
}
}else {
buffer=buffer.left;
if(buffer==null){
node.parent=parent;
parent.left=node;
break;
}
}
}
}
}
//查找元素(find node in Binary tree)
this.find=function (element) {
var node = this.root;
while(true){
if(node==null||node.element==element){
return node;
}else if(node.element<element){
node=node.right;
}else if(node.element>element){
node=node.left;
}
}
}
//查找最小值(get the min node in Binary tree)
this.getMin=function (element) {
var node=this.find(element);
while(node.left!=null){
node=node.left;
}
return node;
}
//查找最大值(get the max node in Binary tree)
this.getMax=function (element) {
var node=this.find(element);
while(node.right!=null){
node=node.right;
}
return node;
}
//移除节点(Remove node from binary tree)
this.remove=function (element) {
var node=this.find(element);
//要移除的节点为空（The node to be removed is null）
if(node==null)
return;
//移除的为根节点（Removed as root node）
if(node.parent==null){
//节点的右节点不为空（The right node of the node is not null）
if(node.right!=null){
this.root=node.right;
this.root.parent=null;
var minNode=this.find(node.right.element);
minNode.left=node.left;
}else{//节点的右节点为空（The right node of the node is null）
this.root=node.left;
this.root.parent=null;
}
}else{//移除的不为根节点（Removed is not the root node）
var parent=node.parent;
if(parent.element<node.element){
if(node.right!=null){
var minNode=this.geMin(node.right.element);
minNode.left=node.left;
node.left.parent=minNode;
parent.right=node.right;
node.right.parent=parent;
}else {
parent.right=node.left;
if(node.left!=null)
node.left.parent=parent;
}
}else{
if(node.right!=null){
var minNode=this.geMin(node.right.element);
minNode.left=node.left;
node.left.parent=minNode;
parent.left=node.right;
node.right.parent=parent;
}else {
parent.left=node.left;
if(node.left!=null)
node.left.parent=parent;
}
}
}
}
//中序遍历（In-order traversal）
this.InSort=function (node) {
if(node!=null){
this.insort(node.left);
console.log(node.show())
this.insort(node.right);
}
}
//前序遍历（Pre-order traversal）
this.PreSort=function (node) {
if(node!=null){
console.log(node.show())
this.insort(node.left);
this.insort(node.right);
}
}
//后序遍历（post-order traversal）
this.PostSort=function (node) {
if(node!=null){
this.insort(node.left);
this.insort(node.right);
console.log(node.show())
}
}
}
var bst=new BST();
bst.insert(23);
bst.insert(45);
bst.insert(16);
bst.insert(37);
bst.insert(3);
bst.insert(99);
bst.insert(22);
//中序遍历
// bst.InSort(bst.root)
//前序遍历
//bst.PreSort(bst.root)
//后序遍历
bst.PostSort(bst.root);
</script>
</html>data structure, binary tree, preorder traversal, postorder traversal, inorder traversal, remove node