Cod sursa(job #731014)
Utilizator | Data | 7 aprilie 2012 12:16:20 | |
---|---|---|---|
Problema | Dezastru | Scor | 80 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.44 kb |
#include<fstream>
using namespace std;
int n,k1,x[30],nrc;
double p[30],probfinal;
ofstream out("dezastru.out");
inline void back(int k,double prob)
{
if(k>k1)
{
probfinal+=prob;
++nrc;
}
else
for(int i=x[k-1]+1;i<=n-k1+k;++i)
{
x[k]=i;
back(k+1,prob*p[i]);
}
}
int main()
{
ifstream in("dezastru.in");
in>>n>>k1;
for(int i=1;i<=n;i++)
in>>p[i];
back(1,1.0);
out<<probfinal/nrc;
return 0;
}