Cod sursa(job #1857377)
Utilizator | Ahmed Hamza Aydin OFY4 | Data | 26 ianuarie 2017 09:33:25 |
---|---|---|---|
Problema | Aria | Scor | 10 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.54 kb |
#include <fstream>
#include <iostream>
using namespace std;
ifstream in("aria.in");
ofstream out("aria.out");
const int Max = 100007;
int n;
double s = 0;
struct coordonate
{
double x, y;
}v[Max];
void alan()
{
for(int i = 1; i <= n; ++i)
{
s+= v[i].x * v[i + 1].y - v[i + 1].x * v[i].y;
}
}
int main()
{
in >> n;
for(int i = 1; i <= n; ++i)
in >> v[i].x >> v[i].y;
v[n + 1].x = v[1].x;
v[n + 1].y = v[1].y;
alan();
out << s / 2 << "\n";
return 0;
}