Cod sursa(job #2571663)
Utilizator | Anda Epure andaraluca2001 | Data | 5 martie 2020 09:21:45 |
---|---|---|---|
Problema | Aria | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.49 kb |
#include <bits/stdc++.h>
using namespace std;
const int MAX=100009;
int n;
struct punct
{
long double x,y;
};
punct v[MAX];
ifstream in("aria.in");
ofstream out("aria.out");
long double a;
int main()
{
in>>n;
for(int i=1;i<=n;i++) in>>v[i].x>>v[i].y;
v[n+1]=v[1];
for(int i=1;i<=n;i++)
{
a+=(v[i].x*v[i+1].y-v[i+1].x*v[i].y);
}
//a+=v[n].x*v[1].y-v[1].x*v[n].y;
out<<setprecision(6)<<fixed<<a/(2.0);
return 0;
}