@lucadani7/algonodejs-for-beginners/dist/LinkedList.js

Just a simple Node.js package with some basic algorithms perfect for people just starting out. It's got easy-to-understand TypeScript versions of stuff like sorting, searching, math with numbers, and messing with strings.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.LinkedList = void 0;
const NodeClass_1 = require("./NodeClass");
class LinkedList {
    constructor() {
        this.head = null;
        this.tail = null;
        this.count = 0;
    }
    addFirst(data) {
        const node = new NodeClass_1.NodeClass(data, this.head);
        this.head = node;
        if (!this.tail) {
            this.tail = node;
        }
        ++this.count;
    }
    addLast(data) {
        const node = new NodeClass_1.NodeClass(data, null);
        if (!this.head) {
            this.head = this.tail = node;
        }
        else {
            this.tail.link = node;
            this.tail = node;
        }
        ++this.count;
    }
    insertAt(data, position) {
        if (position < 0 || position > this.count) {
            throw new RangeError("Index out of bounds!");
        }
        if (position === 0) {
            this.addFirst(data);
            return;
        }
        if (position === this.count) {
            this.addLast(data);
            return;
        }
        let current = this.head;
        for (let i = 0; i < position - 1; current = current.link, ++i)
            ;
        current.link = new NodeClass_1.NodeClass(data, current.link);
        ++this.count;
    }
    remove(data) {
        if (!this.head) {
            return false;
        }
        if (this.head.item === data) {
            this.head = this.head.link;
            if (!this.head) {
                this.tail = null;
            }
            --this.count;
            return true;
        }
        let current = this.head;
        while (current.link && current.link.item !== data) {
            current = current.link;
        }
        if (current.link !== null) {
            if (current.link === this.tail) {
                this.tail = current;
            }
            current.link = current.link.link;
            --this.count;
            return true;
        }
        return false;
    }
    reverse() {
        let previous = null;
        let current = this.head;
        this.tail = this.head;
        while (current) {
            const next = current.link;
            current.link = previous;
            previous = current;
            current = next;
        }
        this.head = previous;
    }
    contains(data) {
        for (let node = this.head; node !== null; node = node.link) {
            if (data === node.item) {
                return true;
            }
        }
        return false;
    }
    get(position) {
        if (position < 0 || position >= this.count) {
            throw new RangeError("Index out of bounds!");
        }
        let node = this.head;
        for (let i = 0; i < position; node = node.link, ++i)
            ;
        return node.item;
    }
    toArray() {
        const result = [];
        for (let node = this.head; node !== null; result.push(node.item), node = node.link)
            ;
        return result;
    }
    fromArray(arr) {
        const list = new LinkedList();
        for (const item of arr) {
            list.addLast(item);
        }
        return list;
    }
    toString() {
        return this.toArray().join(" -> ");
    }
    clone() {
        const copy = new LinkedList();
        for (const item of this) {
            copy.addLast(item);
        }
        return copy;
    }
    equals(other) {
        if (this.count !== other.count) {
            return false;
        }
        const a = this.toArray();
        const b = other.toArray();
        return a.every((val, i) => val === b[i]);
    }
    existsCertainValue(value, compareFn) {
        const cmp = compareFn ?? ((a, b) => a === b);
        return this.toArray().some(x => cmp(x, value));
    }
    getFrequencyRecord() {
        const freq = {};
        for (const val of this) {
            const key = String(val);
            freq[key] = (freq[key] ?? 0) + 1;
        }
        return freq;
    }
    clear() {
        this.head = this.tail = null;
        this.count = 0;
    }
    size() {
        return this.count;
    }
}
exports.LinkedList = LinkedList;