位运算 - Single Number

一，Single Number

题目描述

Given an array of integers, every element appears three times except for one, which appears exactly once. Find that single one.

我的代码

class Solution {
public:
    int singleNumber(vector<int>& nums) {
        int bitnum[32] = {0};
        int res = 0;
        for(int i = 0; i < 32; i ++){
            for(int j = 0; j < nums.size(); j ++){
                bitnum[i] += (nums[j] >> i) & 1;
            }
            res |= (bitnum[i] % 3) << i;
        }
        return res;
    }
};