Quick sort

index.js

function quicksort(array) {
  var sortedArray = array.slice(0); // clone the array
  if(sortedArray.length == 0) return [];

  var left = [], right = [], pivot = sortedArray[0];

  for (var i = 1; i < sortedArray.length; i++) {
    if(sortedArray[i] < pivot) {
      left.push(sortedArray[i]);
    } else {
      right.push(sortedArray[i]);
    }
  }

  return quicksort(left).concat(pivot, quicksort(right));
}

module.exports = quicksort;