Cod sursa(job #3208894)
Utilizator | Data | 1 martie 2024 12:44:55 | |
---|---|---|---|
Problema | Aria | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.51 kb |
#include <fstream>
#include <vector>
#include <cmath>
#include <iomanip>
using namespace std;
ifstream cin("aria.in");
ofstream cout("aria.out");
int n;
vector<long double> X,Y;
long double arie;
int main()
{
cout<<setprecision(5)<<fixed;
cin>>n;
X.resize(n);
Y.resize(n);
for(int i=0;i<n;i++)
cin>>X[i]>>Y[i];
for(int i=0;i<n-1;i++)
arie=arie+X[i]*Y[i+1]-Y[i]*X[i+1];
arie=arie+X[n-1]*Y[0]-Y[n-1]*X[0];
arie=abs(arie)/2;
cout<<arie;
return 0;
}