1. AC, 输入 n 个点的坐标,求出所有满足: 该点上下左右都有点,的点 import java.util.*; /** * @author xx * @data 4/23/20 6:47 PM */ public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); List<point> list = new ArrayList<>...