137 Single Number II.js

/**
 * @param {number[]} nums
 * @return {number}
 */
var singleNumber = function(nums) {
  var singleNum = 0;

  for (var i = 0; i < 32; i++) {
    var bit = 0;
    for (var j = 0; j < nums.length; j++) {
      var num = nums[j];

      bit = (bit + ((num >> i) & 1)) % 3;
    }

    singleNum += bit << i;
  }

  return singleNum;
};