Cod sursa(job #3141246)
Utilizator | Georgescu David davidgeo123 | Data | 13 iulie 2023 13:32:44 |
---|---|---|---|
Problema | Factorial | Scor | 90 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.52 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream fin("fact.in");
ofstream fout("fact.out");
long long nrcif(long long n)
{
long long res=0;
while(n)
{
res+=n/5;
n/=5;
}
return res;
}
int main()
{
long long target;
fin>>target;
long long MAX=1e17;
long long st=1, dr=MAX;
while(st<dr)
{
long long mij=(dr+st)/2;
if(nrcif(mij)<target)st=mij+1;
else dr=mij;
}
if(nrcif(st)==target)fout<<st;
return 0;
}