题解 | 序列找数

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        int n = in.nextInt();
        Integer[] subArry = new Integer[n];
        for (int i = 0; i < n; i++) {
            subArry[i] = in.nextInt();
        }
        for (int i = 0; i < n; i++) {
            boolean inSub = false;
            for (int j = 0; j < n; j++) {
                if (i == subArry[j]) {
                    inSub = true;
                    break;
                }
            }
            if (!inSub) {
                System.out.print(i + " ");
            }
        }
    }
}