网易雷火第一题代码 import java.util.ArrayList; import java.util.List; import java.util.Scanner; public class Main1 { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); if (n == 0 ) { System.out.println(0); } else { List<Integer> list = new ArrayList<>(); for (int i = 0; i < n; i++) { int value = sc.nextInt(); if (!list.contains(value)) list.add(value); } System.out.println(list.size()); } } }