暴力枚举nlong(n)

import java.util.*;

public class Main {
    static int[] a = new int[10010];
    static int idx = 1;

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        sc.nextLine();

        for (int i = 1; i <= n; i++) toArr(sc.nextLine().split(" "));

        Arrays.sort(a, 1, idx);

        int x = -1, y = -1;
        for (int i = 2; i < idx; i++) {
            if (x == -1 && a[i] != a[i - 1] + 1 && a[i] != a[i - 1]) x = a[i - 1] + 1;
            if (y == -1 && a[i] == a[i - 1]) y = a[i];
        }

        System.out.println(x + " " + y);
    }

    static void toArr(String[] str) {
        for (int i = 0; i < str.length; i++) a[idx ++] = Integer.parseInt(str[i]);
    }
}

开数组时间复杂度：m(数据范围)对于本题m = 10^5

import java.util.*;

public class Main {
    static final int N = 10010;
    static int[] a = new int[N];
    static boolean[] st = new boolean[N * 10];
    static int idx = 1, min = 100100;

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();
        sc.nextLine();

        for (int i = 1; i <= n; i++) toArr(sc.nextLine().split(" "));

        int x = -1, y = -1;
        for (int i = 1; i < idx; i++) {
            if (st[a[i]]) y = a[i];
            st[a[i]] = true;
        }

        for (int i = min; x == -1; i++) {
            if (!st[i]) x = i;
        }

        System.out.println(x + " " + y);
    }

    static void toArr(String[] str) {
        for (int i = 0; i < str.length; i++) {
            a[idx] = Integer.parseInt(str[i]);
            min = Math.min(min, a[idx++]);
        }
    }
}