[算法]从十亿个数中找出不重复的数字

import java.util.*;

public class SelectOnlys {
    long S1 = 2 ^ 16;


    int whichSeg(long s) {
        long L = S1;
        int flag = 0;
        while (s >= L) {
            s %= L;
            flag++;
        }
        return flag;
    }

    Collection<Integer> run(long[] a) {
        int[] count = new int[2 ^ 16];
        Collection<Integer> res = new ArrayList<Integer>();
        for (int i = 0; i < a.length; i++) {
            int seg = whichSeg(a[i]);
            int rem = (int) (a[i] % S1);

            if ((count[rem] & (1 << (2 * seg))) != 1) {
                count[rem] |= 1 << (2 * seg);
            } else if ((count[rem] & (1 << (1 + 2 * seg))) != 1) {
                count[rem] |= 1 << (1 + 2 * seg);
            }

        }

        for (int i = 0; i < a.length; i++) {
            int[] b = {1, 3, 5, 7};
            for (int one : b) {
                if ((count[i] & (1 << one)) != 1 && (count[i] & (1 << (one - 1))) == 1) {
                    res.add((int) (long) (one * S1 + a[i]));
                }
            }

        }
        return res;

    }

}