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Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

  p "The Collatz conjecture is defined as follows: start with any positive integer n.
    | If the term is even, divide it by 2.
    | Otherwise, multiply by 3 and add 1.
    | The conjecture is that no matter what value of n, the sequence will always reach 1."
    a(href="https://en.wikipedia.org/wiki/Collatz_conjecture") Learn more !
  p Move the numbers around to reoganize the graph
  p Built using 
    a(href="http://getspringy.com/" target="_blank") springy.js 
    | and made with 💗 by 
    a(href="https://codepen.io/ninivert" target="_blank") ninivert
              // CSS isn't the best, but hey it works

@import url('https://fonts.googleapis.com/css?family=Roboto');

body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #ffdd59;
#canvas {
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  background: white;
  transition: all .4s;
  transform-origin: 100% 50%;
  &.animated {
    transform: scale(.6);
    box-shadow: 0 .5em 2em rgba(black, .6);
  z-index: 1;
.buttons {
  position: absolute;
  top: 0;
  left: 0;
  i {
    padding: .5em;
    box-sizing: border-box;
    color: #1e272e;
    font-size: 1.5em;
    cursor: pointer;
  z-index: 2;
#popup {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 40vw;
  padding: 1em;
  box-sizing: border-box;
  z-index: 0;
  p {
    color: #1e272e;
    font-family: 'Roboto', Arial;
              const dom = {
  info: document.getElementById('info'),
  popup: document.getElementById('popup'),
  canvas: document.getElementById('canvas'),
  download: document.getElementById('download'),
  clear: document.getElementById('clear'),
  new: document.getElementById('new')


// Canvas stuff

dom.canvas.width = window.innerWidth;
dom.canvas.height = window.innerHeight;
window.onresize = () => {
  dom.canvas.width = window.innerWidth;
  dom.canvas.height = window.innerHeight;

// Graph and variable init

let graph = new Springy.Graph();
let numbers = [], nodes = [];
$("#canvas").springy({ graph: graph });

function addBranches(N, min, max) {
  for (let i=0; i<N; i++) {
    // Find valid number to start with
    n = 10;
    let j;
    for (j=0; j<100 && numbers.indexOf(n) !== -1; j++) {
      n = Math.floor(Math.random() * (max-min) + min);
    if (j < 100) addBranch(n);

addBranches(10, 2, 20)

// Add new branch 

function addBranch(n) {
    create starting node that DOES NOT EXIST
    do Collatz
    if new node exists, connect to it and break
    else create that new node and connect, continue in the loop
  // Node already exists in the graph
  if (numbers.indexOf(n) !== -1) return false;
  // Create the node
  currNode = graph.newNode({ label: n.toString() });

  while (n !== 1) {
    // Collatz conjecture
    if (n % 2 === 0) {
      n = n / 2;
    } else {
      n = n * 3 + 1;
    // Connect to next step
    nextNodeIndex = numbers.indexOf(n);
    if (nextNodeIndex === -1) {
      // Next node does not exist
      // Create a new node
      nextNode = graph.newNode({ label: n.toString() });
      // Connect to it
      graph.newEdge(currNode, nextNode);
      // Recursion
      currNode = nextNode;
    } else {
      // Node exists
      graph.newEdge(currNode, nodes[nextNodeIndex]);

// Clear the nodes

function clear() {
  for (node of nodes) {
  numbers = [];
  nodes = [];

// I don't know jQuery, and even though I imported it because I needed it, I'm not going to use it to look smart :P

// Question/Info

dom.info.addEventListener('click', function(ev) {

// Download (that needs fixing)

dom.download.addEventListener('click', function() {
  // Creating new canvas to display a white background
  let c = document.createElement('canvas'),
      ctx = c.getContext('2d');
  c.width = dom.canvas.width;
  c.height = dom.canvas.height;
  ctx.fillStyle = '#fff';
  ctx.fillRect(0, 0, c.width, c.height);
  ctx.drawImage(dom.canvas, 0, 0);
  // Download new canvas
  let link = document.createElement('a');
  link.download = `Collatz conjecture visualization.jpg`;
  link.href = c.toDataURL('image/png');
  // Need to add the link to the body for Firefox
  link.setAttribute("type", "hidden");

dom.clear.addEventListener('click', function() {
  addBranches(10, 2, 20);

dom.new.addEventListener('click', function() {
  let n = prompt('Enter n: ');
  n = parseInt(n);
  n = Math.max(2, n);
  if (isNaN(n)) return false;
  addBranches(1, n, n);
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