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 TreeNode {
  constructor(key, value = key, parent = null) {
    this.key = key;
    this.value = value;
    this.parent = parent;
    this.children = [];
  }

  get isLeaf() {
    return this.children.length === 0;
  }

  get hasChildren() {
    return !this.isLeaf;
  }
}

class Tree {
  constructor(key, value = key) {
    this.root = new TreeNode(key, value);
  }

  *preOrderTraversal(node = this.root) {
    yield node;
    if (node.children.length) {
      for (let child of node.children) {
        yield* this.preOrderTraversal(child);
      }
    }
  }

  *postOrderTraversal(node = this.root) {
    if (node.children.length) {
      for (let child of node.children) {
        yield* this.postOrderTraversal(child);
      }
    }
    yield node;
  }

  insert(parentNodeKey, key, value = key) {
    for (let node of this.preOrderTraversal()) {
      if (node.key === parentNodeKey) {
        node.children.push(new TreeNode(key, value, node));
        return true;
      }
    }
    return false;
  }

  remove(key) {
    for (let node of this.preOrderTraversal()) {
      const filtered = node.children.filter(c => c.key !== key);
      if (filtered.length !== node.children.length) {
        node.children = filtered;
        return true;
      }
    }
    return false;
  }

  find(key) {
    for (let node of this.preOrderTraversal()) {
      if (node.key === key) return node;
    }
    return undefined;
  }
}

const tree = new Tree(1, 'AB');

tree.insert(1, 11, 'AC');
tree.insert(1, 12, 'BC');
tree.insert(12, 121, 'BG');

[...tree.preOrderTraversal()].map(x => x.value);
// ['AB', 'AC', 'BC', 'BCG']

tree.root.value;              // 'AB'
tree.root.hasChildren;        // true

tree.find(12).isLeaf;         // false
tree.find(121).isLeaf;        // true
tree.find(121).parent.value;  // 'BC'

tree.remove(12);

[...tree.postOrderTraversal()].map(x => x.value);
// ['AC', 'AB']

const binarySearch = (arr, item) => {
  let l = 0,
    r = arr.length - 1;
  while (l <= r) {
    const mid = Math.floor((l + r) / 2);
    const guess = arr[mid];
    if (guess === item) return mid;
    if (guess > item) r = mid - 1;
    else l = mid + 1;
  }
  return -1;
};

binarySearch([1, 2, 3, 4, 5], 1); // 0
binarySearch([1, 2, 3, 4, 5], 5); // 4
binarySearch([1, 2, 3, 4, 5], 6); // -1

const primes = num => {
  let arr = Array.from({ length: num - 1 }).map((x, i) => i + 2),
    sqroot = Math.floor(Math.sqrt(num)),
    numsTillSqroot = Array.from({ length: sqroot - 1 }).map((x, i) => i + 2);
  numsTillSqroot.forEach(x => (arr = arr.filter(y => y % x !== 0 || y === x)));
  return arr;
};

primes(10); // [2, 3, 5, 7]

const quickSort = arr => {
  const a = [...arr];
  if (a.length < 2) return a;
  const pivotIndex = Math.floor(arr.length / 2);
  const pivot = a[pivotIndex];
  const [lo, hi] = a.reduce(
    (acc, val, i) => {
      if (val < pivot || (val === pivot && i != pivotIndex)) {
        acc[0].push(val);
      } else if (val > pivot) {
        acc[1].push(val);
      }
      return acc;
    },
    [[], []]
  );
  return [...quickSort(lo), pivot, ...quickSort(hi)];
};

console.log(quickSort([1, 6, 1, 5, 3, 2, 1, 4])) // [1, 1, 1, 2, 3, 4, 5, 6]

//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/"));
});