Single Number II

Source

• 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?

Java

public class Solution {
    public int singleNumber(int[] nums) {
        int[] count = new int[32];
        for(int i=0; i<32; i++){
            for(int j=0; j<nums.length; j++){
                count[i] += (nums[j]>>i)&1;
            }
            count[i] %= 3;
        }

        int result=0;
        for(int i=0; i<32; i++){
            result += count[i]<<i;
        }
        return result;
    }
}