get spark list

bad.js

//bad

var sequence = (function(data, temp){
  var len = data.length - 1;
  for (var i = 0; i < len; ++i) {
    temp.push(data[i+1] - data[i]);
  }
  return temp.join(',');
})((function(all, buf, user){ 
  var len = all.length;
  while (user = all[--len]) {
    buf.push(~~user.innerHTML.split('<br>')[2].split(':')[1]);
  }
  return buf.sort(function(a,b){
    return a-b
  });
}(document.getElementsByTagName('li'), [])), []);

good.js

// good

var sequence = (function(i, len) {
  var list  = [].slice.call(
    document.getElementsByTagName('li')
  ), 
  buf = [],
  seq = [];
  
  for (i = 0, len = list.length; i < len; ++i) {
    buf.push(~~list[i].innerHTML.split('<br>')[2].split(':')[1]);
  };
  buf = buf.sort(function(a,b){
    return a - b;
  });
  for (i = 0, len = buf.length-1; i < len; ++i) {
    seq.push(buf[i+1] - buf[i]);
  }
  return seq.toString();
}());

result

"2,1,1,1,1,1,1,2,1,5,1,1,1,3,1,1,1,1,1,2,1,2,3,4,2,2,1,3,1,1,1,1,3,4,4,4,1,1,1,1,1,1,1,6,1,1,1,3,5,1,1,4,2,8,4,3,2,1,3,1,4,3,8,6,1,2,6,2,1,2,1,2,3,1,7,4,5,3,4,2,3,2,1,1,1,21,1,6,4,2,2,2,1,1,2,7,2,1,3,2,2,1,1,1,1,1,1,1,1,1,5,1,2,3,2,2,2,1,1,2,2,2,2,1,3,2,1"