[LeetCode]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?

思考：参考这里。

class Solution {
public:
int singleNumber(int A[], int n) {
// IMPORTANT: Please reset any member data you declared, as
// the same Solution instance will be reused for each test case.
int one=0;
int two=0;
int three=0;
for(int i=0;i<n;i++)
{
two|=(one&A[i]);
one^=A[i];
three=~(one&two);
one&=three;
two&=three;
}
return one;
}
};