Cod sursa(job #1027752)
Utilizator | Timofte Bogdan kitz | Data | 12 noiembrie 2013 23:55:07 |
---|---|---|---|
Problema | Aria | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.49 kb |
# include <cstdio>
# include <cmath>
# include <fstream>
# include <iomanip>
# define x first
# define y second
std::ifstream f ("aria.in");
std::ofstream g ("aria.out");
std::pair<double, double> V[100005];
int N;
double sol;
int main ()
{
f >> N;
for (int i = 0; i < N; ++i)
f >> V[i].x >> V[i].y;
V[N] = V[0];
for (int i = 0; i < N; ++i)
sol += (V[i].x * V[i + 1].y - V[i + 1].x * V[i].y);
g<<std::fixed<<std::setprecision(7)<<fabs(sol*0.5);
}