第二题set去重直接A了 public class Main2 { private static Scanner sc = new Scanner(System.in); public static void main(String[] args) { String[] str1 = sc.nextLine().split(" "); int n = Integer.valueOf(str1[0]); int m = Integer.valueOf(str1[1]); String[] str2 = sc.nextLine().split(" "); int[] arrA = new int[n]; for(int i = 0; i < n; ++i) { arrA[i] = Integer.valueOf(str2[i]); } int Q = Integer.valueOf(sc.nextLine().split(" ")[0]); for(int i = 0; i< Q; ++i) { int l = sc.nextInt(); int r = sc.nextInt(); Set<Integer> set = new HashSet<>(); for(int j = l - 1; j < r; j++) { set.add(arrA[j]); } System.out.println(set.size()); } } }