Cod sursa(job #2547467)
Utilizator | Bogdan Sever-Cristian severut | Data | 15 februarie 2020 13:10:31 |
---|---|---|---|
Problema | Aria | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.52 kb |
#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;
ifstream in("aria.in");
ofstream out("aria.out");
struct hatz{
long double x,y;
};
hatz v[100005];
int n;
long double suma;
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){
suma+=v[i].x*v[i+1].y-v[i+1].x*v[i].y;
}
if(suma<0)
suma=-suma;
suma/=2.0;
out<<fixed<<setprecision(10)<<suma<<'\n';
return 0;
}