Cod sursa(job #2265825)
Utilizator | Dinica Andrei Cristian dinicaandrei | Data | 21 octombrie 2018 19:14:35 |
---|---|---|---|
Problema | Factorial | Scor | 45 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.61 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream r("fact.in");
ofstream g("fact.out");
int mini=0, maxi=100000000;
long long zero(long long x)
{
long long S=0;
for(long long i=5;x/i>0;i*=5)
S+=x/i;
return S;
}
int binarysearch(long long x)
{
long long a=1, b=100000000, c;
while(a<b)
{
c=(a+b)/2;
if(zero(c)<x)
a=c+1;
else
b=c-1;
}
if(zero(a)==x)
return a;
else
return -1;
}
int main()
{long long p;
r>>p;
g<<binarysearch(p);
return 0;
}