Single Number II.java

public class Solution {
	/**
	 * @param A : An integer array
	 * @return : An integer 
	 */
    public int singleNumberII(int[] A) {
        // write your code here
        if (A == null || A.length == 0) {
            return -1;
        }
        
        int[] bit = new int[32];
        int result = 0;
        for (int i = 0; i < 32; i++) {
            for (int j = 0; j < A.length; j++) {
                bit[i] += A[j] >> i & 1;
                bit[i] %= 3;
            }
            
            result |= (bit[i] << i);
        }
        
        return result;
    }
}