function printHeap(heap, index, level) {
    if (index >= heap.length) {
        return;
    }
    console.log("  ".repeat(level) + heap[index]);
    printHeap(heap, 2 * index + 1, level + 1);
    printHeap(heap, 2 * index + 2, level + 1);
}

//You can call this function by passing in the heap array and the index of the root node, which is typically 0, and level = 0.

let heap = [3, 8, 7, 15, 17, 30, 35, 2, 4, 5, 9];
printHeap(heap,0,0)

const nums = [1, 2, 3];
const strs = Array.from('est');

nums.push(6);
nums.push(4, 9);
strs.unshift('t');

nums.length;                     // 6
nums[nums.length - 1];           // 9
strs[0];                         // 't'
strs[2];                         // 's'

nums.slice(1, 3);                // [2, 3]
nums.map(n => n * 2);            // [2, 4, 6, 12, 8, 18]
nums.filter(n => n % 2 === 0);   // [2, 6, 4]
nums.reduce((a, n) => a + n, 0); // 25

strs.reverse();                  // ['t', 's', 'e', 't']
strs.join('');                   // 'test'

const nums = new Set([1, 2, 3]);

nums.add(4);
nums.add(1);
nums.add(5);
nums.add(4);

nums.size;                       // 5
nums.has(4);                     // true

nums.delete(4);
nums.has(4);                     // false

[...nums];                       // [1, 2, 3, 5]

nums.clear();
nums.size;                       // 0

const items = new Map([
  [1, { name: 'John' }],
  [2, { name: 'Mary' }]
]);

items.set(4, { name: 'Alan' });
items.set(2, { name: 'Jeff' });

items.size;                      // 3
items.has(4);                    // true
items.get(2);                    // { name: 'Jeff' }

items.delete(2);
items.size;                      // 2

[...items.keys()];               // [1, 4]
[...items.values()];             // [{ name: 'John' }, { name: 'Alan' }]

items.clear();
items.size;                      // 0

class SequentialQueue{	//if you want it to go backwards, too bad
	next(){
		return this.i++;
	}
	constructor(start = 0){
		this.i = start;
	}
}
const que = new SequentialQueue(0);
for(let i = 0; i < 10; i++){
	console.log(que.next());
}

//Disclaimer: I do not condone mass web scraping of ESPN websites, and this is just theoretical code that hasn't been used.

//Scrape player stats off of https://www.espn.com/nfl/team/roster/_/name/phi/philadelphia-eagles

//Example player JS object
/*
{
	"shortName": "S. Opeta",
	"name": "Sua Opeta",
	"href": "http://www.espn.com/nfl/player/_/id/3121009/sua-opeta",
	"uid": "s:20~l:28~a:3121009",
	"guid": "dec19157-e984-f981-3724-498281328c97",
	"id": "3121009",
	"height": "6' 4\"",
	"weight": "305 lbs",
	"age": 27,
	"position": "G",
	"jersey": "78",
	"birthDate": "08/15/96",
	"headshot": "https://a.espncdn.com/i/headshots/nfl/players/full/3121009.png",
	"lastName": "Sua Opeta",
	"experience": 4,
	"college": "Weber State"
}
*/

//The page needs to be focused, so you have to put this code in a bookmarklet and click the page before clicking it. Allegedly.
navigator.clipboard.writeText(JSON.stringify(
    window["__espnfitt__"].page.content.roster.groups.flatMap((group)=>{
        return group.athletes.map((athlete)=>{
            //We can assume all football players are above 100 lbs and below 1000 lbs.
            athlete.weight = parseInt(athlete.weight.substring(0,3));
            
            if(athlete.experience == "R") athlete.experience = 0;
            else athlete.experience = parseInt(athlete.experience);

            //We can assume players are at least 1 foot, or under 10 feet tall.
            athlete.inches = 12 * parseInt(athlete.height.substring(0, 1)); //Add feet in inches
            athlete.inches += parseInt(athlete.height.substring(2).replaceAll("\"", "").trim()); //Add remaining inches

            const monthDayYear = athlete.birthDate.split("/");
            athlete.birthMonth = parseInt(monthDayYear[0]);
            athlete.birthDay = parseInt(monthDayYear[1]);
            athlete.birthYear = parseInt(monthDayYear[2]);
            
            //The only really useful stuff we get from this is Height, weight, left handedness, age, position, and birthday
            return athlete;
        });
    })
, null, "\t")).then(null, ()=>{alert("That failed.")});

//Changes all the team links on this page https://www.espn.com/nfl/stats/team to the team's roster for easier scraping
$$("table > tbody > tr > td > div > div > a").forEach((elm)=>{
	elm.setAttribute("href", elm.getAttribute("href").replace("team/", "team/roster/"));
});

// promisify(f, true) to get array of results
function promisify(f, manyArgs = false) {
  return function (...args) {
    return new Promise((resolve, reject) => {
      function callback(err, ...results) { // our custom callback for f
        if (err) {
          reject(err);
        } else {
          // resolve with all callback results if manyArgs is specified
          resolve(manyArgs ? results : results[0]);
        }
      }

      args.push(callback);

      f.call(this, ...args);
    });
  };
}

// usage:
f = promisify(f, true);
f(...).then(arrayOfResults => ..., err => ...);

// `date` is a `Date` object
const formatYmd = date => date.toISOString().slice(0, 10);

// Example
formatYmd(new Date());      // 2020-05-06