var R = require("ramda");

function quickSort(list) {
  var len = R.length(list);
  if (len == 0 || len == 1) return list;
  var pivot = R.last(list);

  var firstHalf = R.filter(i => i<= pivot, R.init(list));
  var secondHalf = R.filter(i => i> pivot, R.init(list));
  return R.concat(quickSort(firstHalf), R.prepend(pivot, quickSort(secondHalf)));
}

console.log('QUICK SORT:', quickSort([1, 9, 3, 10, 5, 4, 6, 7, 8, 2]));