code warriors 551dd1f424b7a4cdae0001f0

double cola.js

function whoIsNext(names, r){
  var x = names.length;
  var pass = ((r - 1)/x) + 1;
  var cycle = Math.log(pass)/Math.LN2;
  var grouping = Math.pow(2, Math.floor(cycle));
  var cbegin = (grouping - 1) * x;

  var r_offset = r - cbegin - 1;
  var r_index = Math.floor(r_offset / grouping);

  return [x, pass, cycle, grouping, cbegin, r_offset, r_index, names[r_index]];
}