Cod sursa(job #2705038)
Utilizator | Data | 11 februarie 2021 20:05:07 | |
---|---|---|---|
Problema | Dezastru | Scor | 20 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.62 kb |
#include <fstream>
#include <vector>
#include <algorithm>
#include <iomanip>
using namespace std;
ifstream be("dezastru.in");
ofstream ki("dezastru.out");
int n,k;
float x[30];
double b[26];
long double db;
int main()
{
be>>n>>k;
for(int i=1;i<=n;i++)
be>>x[i];
vector<int>v;
for(int i=1;i<=n;i++)
v.push_back(i);
b[0]=1;
int m=0;
do{
for(int i=1;i<=k;i++){
b[i]=b[i-1]*x[v[i]];
}
m++;
db+=b[k];
}while(next_permutation(v.begin(),v.end()));
ki<<setprecision(6)<<db/m<<endl;
return 0;
}