Cod sursa(job #2510522)
Utilizator | Bogdan Rulea BogdanRulea | Data | 16 decembrie 2019 20:32:32 |
---|---|---|---|
Problema | Aria | Scor | 70 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.51 kb |
#include <fstream>
#include <cmath>
#include <iomanip>
using namespace std;
ifstream cin("aria.in");
ofstream cout("aria.out");
int n;
struct punct
{
double x,y;
} v[100005];
double sol;
void read()
{
cin>>n;
for(int i=1; i<=n; i++)
cin>>v[i].x>>v[i].y;
}
void solve()
{
v[n+1]=v[1];
for(int i=1; i<=n; i++)
sol+=(v[i].x*v[i+1].y-v[i+1].x*v[i].y);
cout<<fixed<<setprecision(6)<<fabs(sol/2.0);
}
int main()
{
read();
solve();
return 0;
}