Cod sursa(job #2600219)
Utilizator | Character Me CharacterMe | Data | 12 aprilie 2020 12:02:50 |
---|---|---|---|
Problema | Aria | Scor | 70 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.52 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream fin("aria.in");
ofstream fout("aria.out");
int n;
double sol;
pair<double, double> points[100005];
int main()
{
fin >> n;
for(int i = 1; i <= n; ++i) fin >> points[i].first >> points[i].second;
points[n + 1] = points[1];
for(int i = 1; i <= n; ++i){
sol = sol + (points[i + 1].second * points[i].first - points[i + 1].first * points[i].second);
}
fout << fixed << setprecision(6) << sol / 2.0;
return 0;
}