40求助

#include <bits/stdc++.h>
using namespace std;
int n;
int a[100010];
int dp[100010];
int main() {
    ios::sync_with_stdio (false);
    cin.tie (0);
    cout.tie (0);
	cin >> n;
	for (int i = 1; i <= n; i++)
		cin >> a[i];
	for (int i = 1; i <= n; i++)
		dp[i] = 1;
	for (int i = 2; i <= n; i++) {
		for (int j = 1; j < i; j++) {
			if (a[j] < a[i])
				dp[i] = max (dp[i], dp[j] + 1);
		}
	}
	cout << dp[n] << '\n';
    return 0;
}