Ai giúp mình bài này với. Code C++

`\color{red}{\text{@hoangduy67}}`

#include <bits/stdc++.h>
#define ll long long
using namespace std;
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    ll n,k; cin>>n>>k;
    ll a[n+1],s[n+1]; s[0] = 0;
    for (int i=1;i<=n;++i){
        cin>>a[i];
        s[i]=s[i-1]+a[i];
    }
    ll ans = LLONG_MIN;
    for (int i=k;i<=n;++i){
        ans = max(ans,s[i]-s[i-k]);
    }
    cout<<ans;
    return 0;
}

#include <bits/stdc++.h>
using namespace std;
int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    long long n, k;
    cin >> n >> k;
    vector<long long> s(n + 1);
    for (int i = 1; i <= n; ++i) {
        cin >> s[i];
        s[i] += s[i - 1];
    }
    long long ans = LLONG_MIN;
    for (int i = k; i <= n; ++i) {
        ans = max(ans, s[i] - s[i - k]);
    }
    cout << ans;
}