Cod sursa(job #2509220)
Utilizator | Hurjui Alexandru-Mihai hurjui12Alexandru | Data | 13 decembrie 2019 23:14:42 |
---|---|---|---|
Problema | Aria | Scor | 10 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.52 kb |
#include <fstream>
#include <iomanip>
using namespace std;
ifstream fin("aria.in");
ofstream fout("aria.out");
int main()
{
int n, i;
double x1, y1, x = 0, y = 0, xx, yy;
double aria = 0;
fin >> n >> x1 >> y1;
xx = x1;
yy = y1;
for (i = 2; i<=n; i++)
{
fin >> x >> y;
aria = aria + xx*y - x*yy;
xx = x;
yy = y;
}
aria = aria + x*y1 - x1*y;
aria = aria / 2;
if (aria < 0)
aria = aria * (-1);
fout << setprecision(6) << aria;
return 0;
}