Leetcode 137 Single Number II

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?

Solution 1: Use a count[32] to record counter of each bit in nums, for bit in final result, it rely on where count%3=0 or not.

 public class Solution {  
   public int singleNumber(int[] nums) {  
     int[] count=new int[32];  
     for (int x:nums)  
       for (int i=0; i<32; i++)  
         if ((1&x>>i)==1) count[i]++;  
     int res=0;  
     for (int i=0; i<32; i++)  
       if (count[i]%3!=0) res|=1<<i;  
     return res;  
   }  
 }