Cod sursa(job #2353382)

Utilizator MateiAruxandeiMateiStefan MateiAruxandei Data 24 februarie 2019 11:35:44
Problema GFact Scor 40
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.46 kb
#include <fstream>
#include <climits>
#include <cmath>
#include <map>

using namespace std;

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

int p, q, r;
unsigned long long Div[50005];
int cnt = 0;

bool test(unsigned long long val)
{
    for(int i = 2; i <= r; ++i)
    {

        if(Div[i] != 0)
        {
            unsigned long long rez = 0;
            unsigned long long P = i;
            while(val / P != 0)
            {
                rez += val / P;
                P *= i;
            }
            if(rez < Div[i])
                return 0;
        }

    }

    if(cnt == 1)
    {
        unsigned long long rez = 0;
        unsigned long long P = p;
        while(val / P != 0)
        {
            rez += val / P;
            P *= p;
        }
        if(rez < Div[p])
            return 0;
    }
    return 1;
}

int main()
{
    fin >> p >> q;

    int d = 2;
    int cp = p;
    while(p > 1)
    {
        int e = 0;
        while(p % d == 0)
        {
            ++e;
            p /= d;
        }

        Div[d] = e * q;
        if(e * q > 0)
            ++cnt;
        ++d;
    }
    p = cp;

    r = sqrt(p);
    unsigned long long rez = 0;
    unsigned long long st = 1;
    unsigned long long dr = ((1ULL << 45));
    while(st <= dr)
    {
        unsigned long long mij = (st + dr) / 2;
        if(test(mij))
        {
            rez = mij;
            dr = mij - 1;
        }
        else st = mij + 1;
    }
    fout << rez << '\n';
    return 0;
}