class Node {
constructor(val) {
this.val = val;
this.next = null;
this.prev = null;
}
}
class DoublylinkList {
constructor() {
this.head = null;
this.tail = null;
this.length = 0;
}
// 👉👉 Add a new Value to the list
push(val) {
var newNode = new Node(val);
if(this.length === 0) {
this.head = newNode;
this.tail = newNode;
} else {
this.tail.next = newNode;
newNode.prev = this.tail;
this.tail = newNode;
}
this.length++;
console.log( ` You are added ${this.length} Node ->> ${val}` );
return this;
}
// 👉👉 Delete end value in the Node
pop() {
if(!this.head) return undefined;
var poppedNode = this.tail;
if(this.length === 1) {
this.head = null;
this.tail = null;
} else {
this.tail = poppedNode.prev;
}
this.length--;
console.log(` Deleted Successfully 👍`)
return poppedNode;
}
// 👉👉 Delete Head Value in the list
Shift() {
if(!this.head) return undefined;
var oldHead = this.head;
if(this.length === 1) {
this.head = null;
this.tail = null;
} else {
this.head = oldHead.next;
this.head.prev = null;
oldHead.next = null;
}
this.length--;
return oldHead;
}
// 👉👉 Add value in the head in the list
unShift(val) {
var newNode = new Node(val);
if(this.length === 0) {
this.head = newNode;
this.tail = newNode;
} else {
this.head.prev = newNode
newNode.next = this.head;
this.head = newNode;
}
this.length++;
console.log(" -> Added Successfully 👍" );
return this;
}
// Write a Node number and
// Show this number Node name
get(index) {
if(index < 0 || index >= this.length) return null;
if(index <= this.length/2){
var count = 0;
var current = this.head;
while(count != index){
current = current.next;
count++;
}
return current;
} else {
var count = this.length - 1;
var current = this.tail;
while(count !== index){
current = current.next;
count++;
}
return current;
}
console.log(" -> Finded Successfully 👍" );
}
// Change the value in the node
set(index, val) {
var foundNode = this.get(index);
if(foundNode != null) {
foundNode.val = val;
return true;
}
return false;
}
// insert Node
insert(index, val) {
if(index < 0 || index > this.length) return false;
if(index === 0) return this.unShift(val);
if(index === this.length) return this.push(val);
var newNode = new Node(val);
var beforeNode = this.get(index - 1);
var afterNode = beforeNode.next;
beforeNode.next = newNode;
newNode.prev = beforeNode;
newNode.next = afterNode;
afterNode.prev = newNode;
this.length++;
return true;
}
// Remove a Node
remove(index) {
if(index < 0 || index >= this.length) return undefined;
if(index === 0) return this.Shift()
if(index === this.length -1) return this.pop();
var removeNode = this.get(index);
var beforeNode = removeNode.prev;
var afterNode = removeNode.next;
beforeNode.next = afterNode;
afterNode.prev = beforeNode;
// removeNode.prev.next = removeNode.next;
// removeNode.next.next = removeNode.prev;
removeNode.next = null;
removeNode.prev = null;
this.length--;
return removeNode;
}
}
var list = new DoublylinkList()
list.push("Java")
list.push("Java script")
list.push("Html")
list.push("Css")
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