Single Number II

https://leetcode.com/problems/single-number-ii/

https://leetcode.com/discuss/6632/challenge-me-thx

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?

public class Solution {
    public static int singleNumber(int[] nums) {
        int len=nums.length;
        int one=0;int two=0;
        for(int i=0;i<len;i++){
            one=(one^nums[i])&~two;
            two=(two^nums[i])&~one;
        }
        return one;
    }
    public static void main(String[]args){
    int[]nums={1,1,1,2,3,3,3};
    System.out.println(singleNumber(nums));
    }
}