直角，以下代码：

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
#define qwq 1005
using namespace std;
int n, ans;
int a[qwq], dp[qwq];
int main(){
	scanf("%d", &n);
	for(int i = 1;i <= n;i++){
		cin >> a[i];
		dp[i] = 1;
	}
	for(int i = 1;i <= n;i++)
		for(int j = 1;j < i;j++){
			if(a[j] < a[i])
				dp[i] = max(dp[i], dp[j] + 1);
			ans = max(dp[i], ans);
		}
	printf("%d", ans);
	return 0;
}