Cod sursa(job #1963824)

Utilizator BugirosRobert Bugiros Data 12 aprilie 2017 20:14:16
Problema Kperm Scor 90
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.99 kb
#include <fstream>
using namespace std;

const int MODULO = 666013;
const int MAXN = 5010;

ifstream in("kperm.in");
ofstream out("kperm.out");



int n,k,c,r;

int fact[MAXN];

long long putere(int a, int b)
{
    if (b == 0)
        return 1;
    long long nr = putere(a, b / 2);
    if (b % 2 == 0)
        return (nr * nr) % MODULO;
    return (a * nr * nr) % MODULO;
}

int main()
{
    in >> n >> k;
    c = n / k;
    r = n % k;
    if (k % 2 == 0)//imposibil de facut k-permutare
    {
        out << 0 << '\n';
        return 0;
    }

    //altfel raspunsul este r! * (k - r)! * [(c + 1)!] ^ r * (c!) ^ (k - r)

    //ne trebuie factorialele
    fact[0] = 1;
    for (int i = 1;i <= n;++i)
        fact[i] = (fact[i - 1] * i) % MODULO;

    long long rasp = fact[r];
    rasp = (rasp * fact[k - r]) % MODULO;
    rasp = (rasp * putere(fact[c + 1], r)) % MODULO;
    rasp = (rasp * putere(fact[c],k - r)) % MODULO;

    out << rasp << '\n';
    return 0;
}