Cod sursa(job #1220513)
Utilizator | Matraguna Mihai-Alexandru hopingsteam | Data | 17 august 2014 15:44:32 |
---|---|---|---|
Problema | Aria | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.51 kb |
#include <iomanip>
#include <fstream>
using namespace std;
ifstream fin("aria.in");
ofstream fout("aria.out");
const int LIM = 100005;
double x[LIM], y[LIM], Aria;
int n;
void read()
{
fin >> n;
for(int i = 1; i <= n; i++)
fin >> x[i] >> y[i];
// Chestia aia cu capatul
x[n + 1] = x[1];
y[n + 1] = y[1];
//
for(int i = 1; i <= n; i ++)
Aria += x[i] * y[i + 1] - x [i + 1] * y[i];
fout << setprecision(20) << Aria / 2;
}
int main()
{
read();
return 0;
}