Single Number II

Dscription:

Given an array of integers, every element appears three times except for one. Find that single one.

Note:
Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?

Code:

   int singleNumber(vector<int>& nums) {
     int result = 0;
     int n = nums.size();
     int length = 8*sizeof(int);
     for (int i = 0; i < length; ++i)
     {
         int temp = 0;
         for (int j = 0; j < n; ++j)
         {
             if (nums[j] & (1<<i))
                temp++;
         }
         temp %= 3;
         result = result | (temp<<i);
     }
     return result;
    }