题解 | #Redraiment的走法#

import java.util.*;

// 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);
        int n = in.nextInt();
        in.nextLine();
        int i = 0;
        int[] arr = new int[n];
        while (i < n) {
            arr[i] = in.nextInt();
            i++;
        }

        int[] step = new int[arr.length];
        for (i = arr.length - 1; i >= 0; i--) {

            int itemMax = 1;
            for (int k = i + 1; k < arr.length; k++) {
                if (arr[i] < arr[k]) {
                    itemMax = Math.max(itemMax, step[k]+1);

                }
            }
            step[i] = itemMax;
        }

        int max = Arrays.stream(step).max().getAsInt();
        System.out.println(max);
        in.close();
    }
}