code: function(numArray) {
      numArray.sort(function (a, b) {  return a - b;  });
      for (var i=0, prev=0, diff=0, result=[], len=numArray.length; i<len; i++) {
        diff = numArray[i] - prev;
        prev = numArray[i];
        result.push(diff);
      }
      return result;
    }
docs: Converts an array of number values to array of differences between each pairs of values
  for example : [100, 101, 102, 103, 104, 105] => [100, 1, 1, 1, 1, 1]
  @param {array<number>}
  @return {array<number>}