Prime factor card trick (finds card in unsorted deck using prime factor split sorting)

prime-factor-cards.js

// basically, you can guess ANY card by splitting the deck into prime factor piles and placing the pile with their
// chosen card on top every time. After you run out of prime factors for the number of cards in the deck, their card
// will be on top of the chosen pile

const PRIMES = [ 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97 ];

const _ = require('lodash');
const readline = require('readline');
const deckSize = 54;
const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});

// initial deck
var cards = [];
for(let i = 0; i < deckSize; i++) {
  cards.push(i);
}

function factor(number) {
  var rprimes = PRIMES.slice().reverse();
  var factors = [];
  for(let p of rprimes) {
    while(number % p == 0) {
      factors.push(p);
      number /= p;
    }
  }
  return factors.reverse();
}

function distribute(array, sets) {
  var setArrays = [];
  for(let i = 0; i < sets; i++) {
    setArrays.push([]);
  }
  for(let i = 0; i < array.length; i++) {
    setArrays[i % sets].push(array[i]);
  }
  return setArrays;
}

function printStacks(stacks) {
  for(let i = 0; i < stacks[0].length; i++) {
    // for the first one, print a heading
    if(i == 0) {
      console.log(stacks.map((s,j) => j + 1).join('\t'));
      console.log('======================');
    }
    console.log(stacks.map(s => s[i]).join('\t'));
  }
}

function doIteration(cards, remainingFactors) {
  var factor = remainingFactors.splice(0, 1);
  if(!factor.length) { console.log('Your card must be ' + cards[0]); return process.exit(); }

  var stacks = distribute(cards, factor[0]);
  printStacks(stacks);
  rl.question('Which stack is your card in? ', answer => {
    var index = answer - 1;
    doIteration(_.flatten(stacks.splice(index, index + 1).concat(stacks)), remainingFactors);
  });
}

doIteration(cards, factor(deckSize));

// factor(deckSize).forEach(factor => {
//   var stacks = distribute(cards, factor);
//   printStacks(stacks);
//   var index = _.findIndex(stacks, stack => stack.indexOf(targetCard) >= 0); // or prompt the user.
//   cards = _.flatten(stacks.splice(index, index + 1).concat(stacks));
// });
//
// console.log(cards);