Cod sursa(job #2052268)
Utilizator | Bouruc Petru Liviu BourucLiviu | Data | 30 octombrie 2017 12:38:34 |
---|---|---|---|
Problema | Aria | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.48 kb |
#include <fstream>
#include <iomanip>
using namespace std;
ifstream fin ("aria.in");
ofstream fout("aria.out");
struct punct
{
int x, y;
} v[100005];
int main()
{
int n;
double A;
fin >> n;
for(int i = 1; i <= n; ++i) fin >> v[i].x >> v[i].y;
fin.close();
v[n+1] = v[1];
for(int i = 1; i <= n; ++i)
A += (v[i].x*v[i+1].y - v[i+1].x*v[i].y);
fout << setprecision(5) << fixed << A/2;
fout.close();
return 0;
}