Cod sursa(job #490727)
Utilizator | Data | 7 octombrie 2010 17:32:47 | |
---|---|---|---|
Problema | Dezastru | Scor | 80 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.6 kb |
#include<stdio.h>
double ve[27],ss;
char n,k;
int nn;
void back(char p,char t,double x)
{
if(p==k)
{
ss+=x;
nn++;
}else
{
for(char i=t+1;i<=n+p-k+1;++i)
back(p+1,i,ve[i]*x);
}
}
int main()
{
freopen("dezastru.in","r",stdin);
freopen("dezastru.out","w",stdout);
scanf("%d%d",&n,&k);
for(char i=1;i<=n;i++)scanf("%lf",&ve[i]);
if(k==0)printf("100");
else
{
for(char i=1;i<=n-k+1;++i)
back(1,i,ve[i]);
ss=ss/nn;
printf("%.6lf ",ss);
}
return 0;
}