Cod sursa(job #2647115)
Utilizator | Cristian Benghe chriss_b_001 | Data | 3 septembrie 2020 11:36:21 |
---|---|---|---|
Problema | Aria | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.47 kb |
#include <fstream>
#include <iomanip>
using namespace std;
ifstream f("aria.in");
ofstream g("aria.out");
int N;
struct Punct
{
long double x, y;
};
Punct v[100001];
int main()
{
f >> N;
for(int i = 0; i < N; ++i)
f >> v[i].x >> v[i].y;
v[N] = v[0];
long double ans = 0;
for(int i = 0; i < N; ++i)
ans += (v[i].x * v[i + 1].y - v[i + 1].x * v[i].y);
g << fixed<<setprecision(8)<< ans / 2.0;
return 0;
}