text: /**
   *  Created by paper on 15/12/01.
   * 
   *  Single Number III
   *  https://leetcode.com/problems/single-number-iii/
   * 
   *  Given an array of numbers nums, 
   *  in which exactly two elements appear only once and all the other elements appear exactly twice. 
   *  Find the two elements that appear only once.
   *   
   *  For example:
   *  Given nums = [1, 2, 1, 3, 2, 5], return [3, 5].
   *   
   *  Note:
   *  The order of the result is not important. So in the above example, [5, 3] is also correct.
   *  Your algorithm should run in linear runtime complexity. 
   *  Could you implement it using only constant space complexity?
   */
  
  /**
   * @param {number[]} nums
   * @return {number[]}
   */
  var singleNumber = function(nums) {
      var len = nums.length;
      
      if (len === 2) return nums;
      
      var r = nums.sort(function(a, b){return a - b});
      
      var ret = [];
      var t;
      
      for (var i = 0; i < len; i++) {
          t = r[i];
          
          if ( ret[0] === t ) {
              ret.shift();
          } else {
              ret.unshift(t);
          }
      }
      
      return ret;
  };
  