Cod sursa(job #2800840)
Utilizator | Vintila Valentin Ioan minecraft3 | Data | 14 noiembrie 2021 09:18:15 |
---|---|---|---|
Problema | Aria | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.56 kb |
#include <bits/stdc++.h>
using namespace std;
#define N 100005
pair<long double, long double>a[N];
int main()
{
int n;
long double area = 0;
ifstream fin("aria.in");
ofstream fout("aria.out");
fin >> n;
for(int i = 0; i < n; i++){
fin >> a[i].first >> a[i].second;
area += (a[i - 1].first * a[i].second - a[i].first * a[i - 1].second);
}
area += (a[n - 1].first * a[0].second - a[0].first * a[n - 1].second);
area /= 2.0;
fout << fixed << setprecision(6) << area;
}