Cod sursa(job #2951261)

Utilizator Matei_MunteanuMunteanu Matei Ioan Matei_Munteanu Data 5 decembrie 2022 19:44:15
Problema Cowfood Scor 16
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 2.33 kb
#include <bits/stdc++.h> // de scris sursa cu backtracking
using namespace std;

ifstream fin("cowfood.in");
ofstream fout("cowfood.out");
const int MOD = 3210121;

int n, s, k;
int E[24][34];
int sol[24];
int maxi[24][34];
int nr, nr_total;
int fact[10104];
int inv[10104];
int rez;

int putere(int a, int p)
{
    int rez = 1;
    while (p > 0)
    {
        if (p % 2 == 0)
        {
            a = (1LL * a * a) % MOD;
            p /= 2;
        }
        else
        {
            rez = (1LL * rez * a) % MOD;
            p--;
        }
    }
    return rez;
}

void precalc()
{
    fact[0] = 1;
    inv[0] = 1;
    for (int i = 1; i <= s + k + 4; i++)
    {
        fact[i] = (1LL * fact[i - 1] * i) % MOD;
    }
    for (int i = 1; i <= s + k + 4; i++)
    {
        inv[i] = (1LL * inv[i - 1] * putere(i, MOD - 2)) % MOD;
    }
}

int comb(int n, int k)
{
    return (1LL * ((1LL * fact[n] * inv[n - k]) % MOD) * inv[k]) % MOD;
}

void back(int pas)
{
    if (pas == n + 1)
    {
        return;
    }
    for (int i = sol[pas - 1] + 1; i <= n; i++)
    {
        int suma = 0;
        int dif0 = 0;
        for (int j = 1; j <= k; j++)
        {
            maxi[pas][j] = max(maxi[pas - 1][j], E[i][j]);
            suma += maxi[pas][j];
            if (maxi[pas][j] != 0)
                dif0++;
        }
        if (suma <= s && dif0 >= 2)
        {
            int dif = s - suma;
            if (pas % 2 == 0)
            {
                nr_total = (nr_total + comb(dif + k, k));
                if (nr_total > MOD)
                {
                    nr_total -= MOD;
                }
            }
            else
            {
                nr_total = (nr_total - comb(dif + k, k));
                if (nr_total < 0)
                {
                    nr_total += MOD;
                }
            }
        }
        sol[pas] = i;
        back(pas + 1);
    }
}
int main()
{
    fin >> n >> s >> k;
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= k; j++)
        {
            fin >> E[i][j];
        }
    }
    precalc();
    nr_total = (comb(s + k, k) - (k * s) - 1);
    if (nr_total < 0)
    {
        nr_total += MOD;
    }
    back(1);
    fout << nr_total;
    fin.close();
    fout.close();
    return 0;
}