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| class Node {
constructor(key) {
this.key = key
this.leftChild = null
this.rightChild = null
}
}
class AVL {
constructor() {
this.root = null
this.parent = null
this.deleted = null
}
getRoot() {
return this.root
}
_heightNode(node) {
return node === null
? -1
: Math.max(
this._heightNode(node.leftChild),
this._heightNode(node.rightChild)
) + 1
}
_rotationLeftLeft(node) {
let tmp = node.leftChild
node.leftChild = tmp.rightChild
tmp.rightChild = node
return tmp
}
_rotationRightRight(node) {
let tmp = node.rightChild
node.rightChild = tmp.leftChild
tmp.leftChild = node
return tmp
}
_rotationLeftRight(node) {
node.leftChild = this._rotationRightRight(node.leftChild)
return this._rotationLeftLeft(node)
}
_rotationRightLeft(node) {
node.rightChild = this._rotationLeftLeft(node.rightChild)
return this._rotationRightRight(node)
}
_insertNode(node, value) {
if (node === null) {
node = new Node(value)
} else if (value < node.key) {
node.leftChild = this._insertNode(node.leftChild, value)
if (node.leftChild !== null) {
if (
this._heightNode(node.leftChild) - this._heightNode(node.rightChild) >
1
) {
if (value < node.leftChild.key) {
node = this._rotationLeftLeft(node)
} else {
node = this._rotationLeftRight(node)
}
}
}
} else if (value > node.key) {
node.rightChild = this._insertNode(node.rightChild, value)
if (node.rightChild !== null) {
if (
this._heightNode(node.rightChild) - this._heightNode(node.leftChild) >
1
) {
if (value > node.rightChild.key) {
node = this._rotationRightRight(node)
} else {
node = this._rotationRightLeft(node)
}
}
}
}
return node
}
insert(value) {
this.root = this._insertNode(this.root, value)
}
_removeNode(node, value) {
if (node === null) return node
this.parent = node
if (value < node.key) {
node.leftChild = _removeNode(node.leftChild, value)
} else {
this.deleted = node
node.rightChild = _removeNode(node.rightChild, value)
}
if (node === this.parent) {
if (this.deleted !== null && value === this.deleted.key) {
if (this.deleted === this.parent) {
node = node.leftChild
} else {
;[this.deleted.key, this.parent.key] = [
this.parent.key,
this.deleted.key,
]
node = node.rightChild
}
}
} else {
if (
this._heightNode(node.leftChild) - this._heightNode(node.rightChild) ===
2
) {
if (value < node.leftChild.key) {
node = this._rotationLeftRight(node)
} else {
node = this._rotationLeftLeft(node)
}
}
if (
this._heightNode(node.rightChild) - this._heightNode(node.leftChild) ===
2
) {
if (value > node.rightChild.key) {
node = this._rotationRightLeft(node)
} else {
node = this._rotationRightRight(node)
}
}
}
return node
}
remove(value) {
this.parent = null
this.deleted = null
this.root = this._removeNode(this.root, value)
}
inOrderTraverse() {
this._inOrderTraverse(this.root)
}
_inOrderTraverse(node) {
if (node) {
this._inOrderTraverse(node.leftChild)
console.log(node.key)
this._inOrderTraverse(node.rightChild)
}
}
}
let avl = new AVL()
avl.insert(6)
avl.insert(7)
avl.insert(14)
avl.insert(15)
avl.insert(13)
console.log(avl.getRoot())
avl.inOrderTraverse()
|