题解 | #Redraiment的走法#

import java.util.*;

public class Main {
    public static void main(String args[]) {
        Scanner scan = new Scanner(System.in);
        while (scan.hasNext()) {
            int n = scan.nextInt();
            int [] a = new int[n];
            for (int i = 0; i < n; i++) {
                a[i] = scan.nextInt();
            }
            
            int [] maxl = new int[n];//存储到各点的最长步数
            int [] maxa = new int[n];//存储各最长步数对应的最大梅花桩高度
            maxl[0] = 1;
            maxa[0] = a[0];
            for (int i = 1 ; i < n; i++) {
                int index = i;
                int maxlen = 1;
                for (int j = i - 1; j >=0; j--) {
                    if (a[i] > maxa[j]) {//a[i]的值动态更新，不要把状态值都压缩到maxl[i]而后续i+1处直接通过maxl[i]计算；应该通过多个状态值maxl[0]-maxl[i-1]计算maxl[i]，即人人为我；新的参数a[i]，我为人人，a[i]用于参与maxl[0]-maxl[i]的运算
                        if (maxl[j] + 1 > maxlen) {
                            index = j;
                            maxlen = maxl[j] + 1;                             
                        }
                    }
                    
                }
                maxl[i] = maxl[index] + 1;
                maxa[i] = a[i];
            }
            int maxlen = 0;
            for (int i = 0 ; i < a.length; i++) {
                if (maxl[i] > maxlen) {
                    maxlen = maxl[i];
                }
            }
            System.out.println(maxlen);
        }
    }
}