多人围一圈报数问题
public static void str() {
List<Integer> list = new ArrayList<Integer>();
List<Integer> list1 = new ArrayList<Integer>();
for (int i = 0; i < 9; i++) {
list.add(i + 1);
}

int k = 0;
long time = System.currentTimeMillis();
while (list.size() > 0) {
for (Integer j : list) {
k++;
if (k % 3 == 0) {
System.out.print(j + " ");
list1.add(j);
}
}
list.removeAll(list1);
list1.clear();
}
System.out.println("耗时：" + (System.currentTimeMillis() - time));
}