Cod sursa(job #1124063)
Utilizator | Data | 26 februarie 2014 11:10:50 | |
---|---|---|---|
Problema | Dezastru | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.44 kb |
#include <fstream>
using namespace std;
ifstream fin("dezastru.in");
ofstream fout("dezastru.out");
int main()
{
int i,j,n,m,k=0,f=1;
double a[25],b[25],s=0;
fin>>n>>m;
for(i=0;i<n;i++)
fin>>a[i];
for(i=0;i<n-1;i++)
{
for(j=i+1;j<n;j++)
b[k++]=a[i]*a[j];
}
for(i=1;i<=n;i++)
f=f*i;
for(i=0;i<n;i++)
s=s+(b[i]*2)/f;
fout<<s;
return 0;
}