Single Number II

 1 public class Solution {
 2     public int singleNumber(int[] A) {
 3         int bit [] = new int[32];
 4         for(int i=0;i<A.length;i++){
 5             for(int j=0;j<32;j++){
 6                 int rotate = A[i]>>j;
 7                 if(rotate==0) break;
 8                 else bit[j] += rotate&1;
 9             }
10             
11         }
12         int sum = 0;
13         for(int i=0;i<32;i++){
14             sum += bit[i]%3<<i;
15         }
16         return sum;
17     }
18 }