Cod sursa(job #3032919)
Utilizator | Data | 23 martie 2023 08:42:36 | |
---|---|---|---|
Problema | Aria | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.38 kb |
#include <bits/stdc++.h>
#define endl '\n'
using namespace std;
ifstream fin("aria.in");
ofstream fout("aria.out");
int main() {
int n;
fin>>n;
vector<int> x(n), y(n);
for (int i=0; i<n; ++i) fin>>x[i]>>y[i];
double a=0;
for (int i=0; i<n; ++i) {
int j=(i+1)%n;
a += (double)x[i]*y[j] - (double)x[j]*y[i];
}
a /= 2;
fout<<fixed<<abs(a);
}