Cod sursa(job #1409633)

Utilizator Ionut228Ionut Calofir Ionut228 Data 30 martie 2015 17:06:45
Problema Ferma Scor 40
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.24 kb
#include <fstream>
#include <algorithm>
#include <deque>

using namespace std;

ifstream fin("ferma.in");
ofstream fout("ferma.out");

int N, K;
int V[20005], dp[1005][20005], S[20005];
deque<int> DQ;

int main()
{
    fin >> N >> K;
    for (int i = 1; i <= N; ++i)
    {
        fin >> V[i];
        S[i] = S[i - 1] + V[i];
    }
    for (int i = N + 1; i <= 2 * N + 1; ++i)
    {
        V[i] = V[i - N];
        S[i] = S[i - 1] + V[i];
    }
    dp[1][1] = max(0, V[1]);
    DQ.push_back(1);
    for (int i = 2; i <= N; ++i)
    {
        dp[1][i] = max(dp[1][i - 1], S[i] - S[DQ.front()]);

        while (!DQ.empty() && S[i] <= S[DQ.back()])
            DQ.pop_back();
        DQ.push_back(i);
    }
    for (int i = 2; i <= K; ++i)
    {
        DQ.clear();
        dp[i][1] = max(0, V[1]);
        DQ.push_back(1);
        for (int j = 2; j <= N; ++j)
        {
            dp[i][j] = max(dp[i][j - 1], dp[i - 1][DQ.front()] + S[j] - S[DQ.front()]);
            while (!DQ.empty() && (dp[i - 1][j] - S[j] >= dp[i - 1][DQ.back()] - S[DQ.back()]))
                DQ.pop_back();
            DQ.push_back(j);
        }
    }

    fout << dp[K][N] << '\n';

    fin.close();
    fout.close();
    return 0;
}