Single Number II

参考链接1 和 参考链接2

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