Cod sursa(job #2764687)
Utilizator | Dragutoiu Vlad-Ioan levladiator | Data | 22 iulie 2021 10:59:24 |
---|---|---|---|
Problema | Aria | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.49 kb |
#include <fstream>
#include <iomanip>
using namespace std;
ifstream f("aria.in");
ofstream g("aria.out");
int main()
{
int N;
long double x1, y1, x2, y2, x3, y3,
A = 0;
f >> N >> x1 >> y1;
x2 = x1;
y2 = y1;
while(--N)
{
f >> x3 >> y3;
A += x2 * y3 - x3 * y2;
x2 = x3;
y2 = y3;
}
A += x2 * y1 - x1 * y2;
A /= 2;
if(A < 0) A = -A;
g << fixed << setprecision(6) << A;
return 0;
}