大佬求调！全测试点红紫

代码
#include<bits/stdc++.h>
using namespace std;
int n,a[5000],f[5000];
int main ()
{
    cin >>n;
    for (int i = 1;i<=n;i++)
    {
        cin >>a[i];
    }
    f[1] = a[1];
    int ans = f[1];
    for (int i = 1;i<=n;i++)
    {
        f[i] = a[i];
        for (int j = 1;j<=i-1;j++)
        {
            if (a[j]<a[i])
            {
                f[i]=max(f[i],f[j]+a[i]);
            }
        }
        ans = max(ans,f[i]);
    }
    cout <<ans;
    return 0;
}