linked list

linkedList.ts

class NodePoint<T> {
    value: T;
    next: NodePoint<T> | null;

    constructor(value: T) {
        this.value = value;
        this.next = null;
    }
}

class LinkedList<T> {
    first: NodePoint<T> | null;

    constructor(firstNode: NodePoint<T>) {
        this.first = firstNode;
    }

    indexOf(value: T): number {
        var currentIndex = 0;
        var currentNode = this.first;

        if (currentNode?.value === value) {
            return currentIndex;
        }

        while (currentNode!.next) {
            currentNode = currentNode!.next;
            currentIndex += 1;

            if (currentNode.value === value) {
                return currentIndex;
            }
        }

        return -1;
    }

    read(index: number): T {
        var currentIndex = 0;
        var currentNode = this.first;

        while (currentIndex < index) {
            currentIndex += 1;
            currentNode = currentNode!.next;
        }

        return currentNode!.value;
    }

    insertAtIndex(index: number, value: T): void {
        const newNodePoint = new NodePoint<T>(value);

        if (index === 0) {
            newNodePoint.next = this.first;
            this.first = newNodePoint;
            return;
        }

        var currentNode = this.first;
        var currentIndex = 0;
        while (currentIndex < (index - 1)) {
            currentNode = currentNode!.next;
            currentIndex += 1;
        }

        newNodePoint.next = currentNode!.next;
        currentNode!.next = newNodePoint;
    }

    deleteAtIndex(index: number) {
        var currentIndex = 0;
        var currentNode = this.first;

        if (index === 0) {
            this.first = currentNode!.next;
            return;
        }

        while (currentIndex < (index - 1)) {
            currentNode = currentNode!.next;
            currentIndex += 1;
        }

        currentNode!.next = currentNode!.next!.next;
    }
}

var firstNode = new NodePoint<number>(3);
var secondNode = new NodePoint<number>(5);
var thirdNode = new NodePoint<number>(8);

firstNode.next = secondNode;
secondNode.next = thirdNode;

//console.log(firstNode.next);
//console.log(secondNode.next);

var linkedList = new LinkedList<number>(firstNode);

linkedList.insertAtIndex(2, 99)

//console.log(firstNode.next);
//console.log(secondNode.next);

const num = linkedList.read(2);
console.log(num);

const num1 = linkedList.indexOf(99);
console.log(num1);