Cod sursa(job #2211151)
Utilizator | Tutuldunsa Voronokda zvon | Data | 9 iunie 2018 14:17:53 |
---|---|---|---|
Problema | Aria | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.48 kb |
#include<iostream>
#include<fstream>
#include<iomanip>
using namespace std;
int n;
ifstream fi("aria.in");
ofstream fo("aria.out");
int xs[100005];
int ys[100005];
int main() {
double aria = 0;
fi >> n;
for (int i = 0; i < n; i++) {
fi >> xs[i] >> ys[i];
}
for (int i = 0; i < n - 1; i++) {
aria += (xs[i] * ys[i + 1] - xs[i + 1] * ys[i]);
}
aria += xs[n - 1] * ys[0] - xs[0] * ys[n - 1];
aria *= 0.5;
fo << setprecision(5) << aria;
fi.close();
fo.close();
return 0;
}