记录一下这个do while,简单直接有效,除了有点不够高效 import java.util.*; public class Main{ public static void main(String[] args){ Scanner in =new Scanner(System.in); do{ int N=in.nextInt(); int idx=0; int[] buf=new int[1001]; Arrays.fill(buf,0); while(idx++<N){ int tmp=in.nextInt(); buf[tmp]=buf[tmp]|1; } for(int i=...