Cod sursa(job #1378364)
Utilizator | Data | 6 martie 2015 11:48:30 | |
---|---|---|---|
Problema | Aria | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.44 kb |
#include <fstream>
#include <cmath>
#include <iomanip>
using namespace std;
ifstream f("aria.in");
ofstream g("aria.out");
struct arie
{
double x, y;
};
arie v[100001];
int i,n;
double s=0;
int main()
{
f>>n;
for (i=1; i<=n; ++i)
f>>v[i].x>>v[i].y;
v[n+1]=v[1];
for (i=1; i<=n; ++i)
s+=(v[i].x*v[i+1].y-v[i+1].x*v[i].y);
g<<fixed<<setprecision(5)<<abs(s/2);
return 0;
}