Cod sursa(job #3197555)
Utilizator | Data | 27 ianuarie 2024 09:48:30 | |
---|---|---|---|
Problema | Aria | Scor | 70 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.49 kb |
#include <iostream>
#include <fstream>
#include <iomanip>
#define NMAX 100003
using namespace std;
ifstream fin ("aria.in");
ofstream fout ("aria.out");
int n;
double x[NMAX], y[NMAX];
long double aria;
int main()
{
fin >> n;
for (int i = 0; i < n; i++)
fin >> x[i] >> y[i];
x[n] = x[0]; y[n] = y[0];
for (int i = 0; i < n; i++)
aria += x[i] * y[i+1] - x[i+1] * y[i];
fout << fixed << setprecision(5) << aria / 2.0;
return 0;
}