小编new*_*ser的帖子

这是我从这里获得的代码示例。

public class Snippet {
    private static final int[] ARRAY = {1, 4, 3, 18, 2, 8, 9, 6, 5, 10,
            11, 12, 13, 14, 15, 16, 17, 19, 0, 20};

    //{1,2,4,5,6,8,7,9,3}
    private int getMissingElem() {
        int XOR = 0;
        for (int i = 0; i < 20; i++) {
            if (ARRAY[i] != 0) {
                XOR ^= ARRAY[i];
            }
            XOR ^= (i + 1);
        }
        return XOR;
    }

    public static void main(String[] args) {
        Snippet s = new …