Mai intai trebuie sa te autentifici.
Cod sursa(job #2106540)
Utilizator | Data | 15 ianuarie 2018 21:36:39 | |
---|---|---|---|
Problema | Pairs | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.58 kb |
#include <fstream>
using namespace std;
ifstream in("pairs.in");
ofstream out("pairs.out");
int frecv[1000010],v[100010];
int main()
{
unsigned long long n,nr,cnt=0,i,max=0,fin=0;
in>>n;
for(i=1; i<=n; i++)
{
in>>v[i];
nr=v[i];
frecv[v[i]]++;
if(max<v[i])
max=v[i];
}
for(i=2; i<=max; i++)
{
nr=i;
cnt=0;
while(nr<=max)
{
cnt+=frecv[nr];
nr+=i;
}
fin+=cnt*(cnt-1)/2;
}
out<<n*(n-1)/2-fin;
return 0;
}