题解 | #E#

#include<bits/stdc++.h>
using namespace std;
#define int long long
typedef pair<int, int> PII;
int n, k;
const int N = 1e4 + 10;
int a[N];
int f[N];
signed main() {
    cin >> n >> k;
    memset(f, -1145141919810, sizeof f);
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        if (i <= 6)
            f[i] = a[i];
    }


    for (int i = 2; i <= k; i++) {
        for (int j = i * 6; j >= i; j--)
        {
            f[j] = -1145141919810;
            for (int q = 1; q <= 6 && (j - q) >= i-1; q++)
                f[j] = max(f[j], f[j - q]);
            f[j] += a[j];
        }
    }

//     for (int i = 1; i <= n; i++)
//         cout << f[i] << " ";
//     cout << endl;
    int res = -1145141919810;
    for (int i = k; i <= n && i <= 6 * k; i++)
        res = max(res, f[i]);
    cout << res;
    return 0;
}