Cod sursa(job #952657)
Utilizator | Darie Sergiu primul | Data | 23 mai 2013 19:26:02 |
---|---|---|---|
Problema | Aria | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.48 kb |
#include<fstream>
#include<iomanip>
using namespace std;
ifstream f("aria.in");
ofstream g("aria.out");
struct point
{
double x,y;
};
double area = 0;
point p[100001];
int n;
int main()
{
f>>n;
for (int i=0;i<n;i++)
f>>p[i].x>>p[i].y;
p[n] = p[0];
f.close();
for (int i=0;i<n;i++)
area += ( (p[i].x*p[i+1].y) - (p[i+1].x*p[i].y) );
g<<setprecision(5)<<fixed<<area/2.0;
g.close();
return 0;
}