题解 | #Redraiment的走法#

import java.util.Arrays;
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
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int a = in.nextInt();
            int[] b = new int[a];
            for (int i = 0; i < a; i++) {
                b[i] = in.nextInt();
            }
            System.out.println(getMaxStep(b));
        }
        in.close();
    }

    private static int getMaxStep(int[] arr) {
        int maxStep = 1;
        int [] dp = new int[arr.length];
        Arrays.fill(dp, 1);
        for (int i = 1; i < arr.length; ++i) {
            for (int j = 0; j < i; ++j) {
                if (arr[j] < arr[i]) {
                    dp[i] = Math.max(dp[i], dp[j] + 1);
                }
            }
            maxStep = Math.max(maxStep, dp[i]);
        }
        return maxStep;
    }
}