Secret Santa

secretSanta.js

const kids = [
  'ifeest@hotmail.com',
  'osawayn@gmail.com',
  'aidan.stracke@hotmail.com',
  'mortimer.miller@ohara.com',
  'runte.luella@hotmail.com',
  'jcassin@crona.net',
  'windler.ardith@upton.com',
  'dean.kozey@tillman.info',
  'gtorp@dibbert.com',
  'alysa33@yahoo.com',
]

const shuffle = (arr: string[]) => {
  let count = 0;
  while(count < arr.length) {
    const elementA = arr[count];
    const randomPosition = Math.floor(Math.random() * count);
    const elementB = arr[randomPosition];

    // Swap a and b
    arr[count] = elementB;
    arr[randomPosition] = elementA;
    count++;
  }

  return arr;
}

const makeSecretSantaPairs = (kids: string[]) => {
  const shuffledKids = shuffle(kids);
  const pairs: string[][] = [];
  const length = shuffledKids.length;

  for(let i = 0; i < shuffledKids.length; i++) {
    // console.log(i, ((i+1) % length));
    pairs.push([shuffledKids[i], shuffledKids[((i+1) % length)]]);
  }

  return pairs;
}

console.log(makeSecretSantaPairs(kids));