Cod sursa(job #937098)

Utilizator darrenRares Buhai darren Data 9 aprilie 2013 18:14:21
Problema Cowfood Scor 54
Compilator cpp Status done
Runda Arhiva de probleme Marime 2.17 kb
#include <cstring>
#include <fstream>
#include <algorithm>

using namespace std;

const int MOD = 3210121;

int K, S, N;
int A[22][32];
int fact[20002], invfact[20002];
int D[10002], E[10002];
int result;

int power(int x, int y)
{
    if (y == 0) return 1;
    if (y & 1) return 1LL * x * power(1LL * x * x % MOD, y >> 1) % MOD;
    return power(1LL * x * x % MOD, y >> 1);
}
int COMB(int x, int y)
{
    int resnow = fact[x];
    resnow = 1LL * resnow * invfact[y] % MOD;
    resnow = 1LL * resnow * invfact[x - y] % MOD;
    return resnow;
}

int main()
{
    ifstream fin("cowfood.in");
    ofstream fout("cowfood.out");

    fact[0] = 1;
    invfact[0] = 1;
    for (int i = 1; i <= 20000; ++i)
    {
        fact[i] = 1LL * fact[i - 1] * i % MOD;
        invfact[i] = 1LL * invfact[i - 1] * power(i, MOD - 2) % MOD;
    }

    fin >> K >> S >> N;
    for (int i = 1; i <= N; ++i)
        for (int j = 1; j <= K; ++j)
            fin >> A[i][j];

    D[0] = 1;
    E[0] = 0;
    for (int i = 1; i <= S; ++i)
    {
        D[i] = D[i - 1] + COMB(i + K - 1, K - 1);
        if (D[i] >= MOD) D[i] -= MOD;

        E[i] = E[i - 1] + COMB(i + K - 1, K - 1);
        if (E[i] >= MOD) E[i] -= MOD;
        E[i] -= K;
        if (E[i] < 0) E[i] += MOD;
    }

    result = E[S];
    for (int i = 1; i < (1 << N); ++i)
    {
        memset(A[0], 0, sizeof(A[0]));
        for (int j = 0; j < N; ++j)
            if (i & (1 << j))
                for (int k = 1; k <= K; ++k)
                    A[0][k] = max(A[0][k], A[j + 1][k]);

        int sumnow = 0;
        for (int j = 1; j <= K; ++j)
            sumnow += A[0][j];

        int remnow = S - sumnow;
        if (remnow < 0) continue;

        int aux = i, numdig = 0;
        while (aux)
        {
            aux &= aux - 1;
            ++numdig;
        }

        if (numdig & 1)
        {
            result -= D[remnow];
            if (result < 0) result += MOD;
        }
        else
        {
            result += D[remnow];
            if (result >= MOD) result -= MOD;
        }
    }

    fout << result << '\n';

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