Cod sursa(job #2603511)
Utilizator | Mihai Cosmin bmc213 | Data | 20 aprilie 2020 11:48:34 |
---|---|---|---|
Problema | Factorial | Scor | 95 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.62 kb |
#include <iostream>
#include <fstream>
std::ifstream f("fact.in");
std::ofstream g("fact.out");
long long nr_zero(long long n)
{
long long s = 0;
while(n)
{
s = s + n / 5;
n /= 5;
}
return s;
}
int st, dr, n, mij, p = -1;
long long nr;
int main()
{
f >> n;
st = 0;
dr = 1e9;
while(st <= dr)
{
mij = (st + dr) / 2;
nr = nr_zero(mij);
if(nr < n)
st = mij + 1;
else
{
if(n == nr)
p = mij;
dr = mij - 1;
}
}
g << p;
return 0;
}