class LinkedList {
constructor(value){
this.head = {
value: value,
next: null
};
this.tail = this.head;
this.length = 1;
}
// append here a new element in the linked list
append(value){
const newNode = {
value: value,
next: null
};
this.tail.next = newNode;
this.tail = newNode;
this.length++;
return this;
}
prepend(value){
const newNode = {
value: value,
next: null
};
newNode.next= this.head;
this.head = newNode;
this.length++;
return this;
}
printList(){
const array = [];
let currentNode = this.head;
while(currentNode.next !== null){
array.push(currentNode.value);
currentNode = currentNode.next;
}
return array;
}
insert(index, value){
const newNode = {
value: value,
next: null
};
if(index >= this.length){
this.append(value);
this.length++;
}
if(index === 0){
this.prepend(value);
this.length++;
}
const leader = this.traverseToIndex(index-1);
const holdingPointer = leader.next;
leader.next = newNode;
newNode.next = holdingPointer;
this.length++;
return this.printList;
}
traverseToIndex(index){
let counter = 0;
let currentNode = this.head;
while(counter !== index){
currentNode = currentNode.next;
counter++;
}
return currentNode;
}
}
const myLinkedList = new LinkedList(10);
myLinkedList.append(20);
myLinkedList.append(30);
myLinkedList.append(40);
myLinkedList.prepend(30);
myLinkedList.insert(44, 99);
console.log(myLinkedList.printList());
// console.log(myLinkedList);
