题解 | #Redraiment的走法#

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }
        //dp[j]表示以下标j为起点,最多走的步数
        int[] dp = new int[n];
        int max = 0;
        for (int j = n - 1; j >= 0; j--) {
            dp[j] = 1;
            for (int k = n - 1; k > j; k--) {
                if (a[j] < a[k]) {
                    dp[j] = Math.max(dp[j], dp[k] + 1);
                }
            }
            max = Math.max(max, dp[j]);
        }
        System.out.println(max);
    }
}