Cod sursa(job #780056)
Utilizator | Data | 19 august 2012 19:29:18 | |
---|---|---|---|
Problema | Dezastru | Scor | 10 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.52 kb |
#include <fstream>
using namespace std;
double a[26], A[26][26];
int n, k, i, j;
long long fac(int z)
{
int p, pr=1;
for(p=1; p<=z; p++)
{
pr=pr*p;
}
return pr;
}
int main()
{
ifstream f("dezastru.in");
ofstream g("dezastru.out");
f>>n>>k;
for(i=1; i<=n; i++)
{
A[i][0]=1;
f>>a[i];
}
A[0][0]=1;
for(i=1; i<=n; i++)
{
for(j=1; j<=k; j++)
{
A[i][j]=A[i-1][j]+A[i-1][j-1]*a[i];
}
}
g.precision(7);
//double combinari=fac(n)/(fac(n-k)*fac(k));
g<<fixed<<A[n][k]/n;
}