CarlaTeo

function reverseLinkedList(head) {
  let prev = null; 
  let cur = head; 
  let next = null; 
  
  while(cur) {
    next = cur.next; 
    cur.next = prev;
    prev = cur;
    cur = next;            

CarlaTeo

function buildBST(sortedArray) {
  if(!sortedArray.length) return null;
  if(sortedArray.length === 1) return new Node(sortedArray[0]);
  
  const rootIndex = Math.floor(sortedArray.length / 2);
  const root = new Node(sortedArray[rootIndex]);
  root.left = buildBST(sortedArray.slice(0, rootIndex));
  root.right = buildBST(sortedArray.slice(rootIndex + 1));
    
  return root;

CarlaTeo

class BSTIterator {
  constructor(root) {
    this.nextValue = null; 
    this.sortedValues = getInOrderValues(root);
  }
  
  hasNext() {
    if(!this.nextValue) {      
      const next = this.sortedValues.next();
      this.nextValue = next.done ? null : next.value;

CarlaTeo

// Problem: https://www.hackerrank.com/challenges/tree-height-of-a-binary-tree/problem

function getHeight(head) {  
  if(!head) return -1;
  const heights = new Set();
  DFS(head, -1, heights); 
  
  return Math.max(...heights);
}

CarlaTeo

// Source problem: https://algorithms.tutorialhorizon.com/colorful-numbers/
// Objective: Given a number, find out whether its colorful or not.
// Colorful Number: When in a given number, product of every digit of a sub-sequence are different. That number is called Colorful Number.
// Given Number : 3245
// Output : Colorful
// Number 3245 can be broken into parts like 3 2 4 5 32 24 45 324 245.
// this number is a colorful number, since product of every digit of a sub-sequence are different.
// That is, 3 2 4 5 (3*2)=6 (2*4)=8 (4*5)=20, (3*2*4)= 24 (2*4*5)= 40

// Given Number : 326

CarlaTeo

function heapSort(array) {
  const heap = heapify(array);
  let lengthToConsider = array.length;
  for(let i = array.length - 1; i > 0; i--) {
    swap(array, i, 0); 
    lengthToConsider--;
    descendHeap(array, lengthToConsider, 0);
  }
}

CarlaTeo

function quickSort(array) { 
  if(array.length <= 1) return array;
  
  const pivot = array[0]; 
  const [left, right] = pivotDivision(array.slice(1), pivot);
  return [...quickSort(left), pivot, ...quickSort(right)]; 
}

function pivotDivision(array, pivot) { 
  const left = []; 

CarlaTeo

function mergeSort(array) { 
  if(array.length <= 1) return array;
  
  const half = Math.floor(array.length / 2);        
  const left = array.slice(0, half);      
  const right = array.slice(half);       
  const sortedLeft = mergeSort(left);   
  const sortedRight = mergeSort(right); 
  
  return merge(sortedLeft, sortedRight); 

CarlaTeo

// Bucket Sort: O(N) method to sort natural numbers

function bucketSort(array) {
  const buckets = [];
  array.forEach(number => {
    if(!buckets[number]) buckets[number] = 1;
    else buckets[number] += 1;
  })
  const sortedArray = [];
  buckets.forEach((counter, number) => {

CarlaTeo

// Using strategy of slower and faster pointers

class Node {
  constructor(data) {
    this.data = data;
    this.next = null;
  }
}

function hasCycle(head) {