Cod sursa(job #1537516)

Utilizator Iustin48Ventaniuc Iustin Iustin48 Data 27 noiembrie 2015 15:03:35
Problema Aria Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include <fstream>
using namespace std;
ifstream f("aria.in");
ofstream g("aria.out");
int n,x[100001],y[100001];
int main()
{
    f>>n;
    for(int i=1;i<=n;++i)
        f>>x[i]>>y[i];
    double s=0;
    for(int i=1;i<n;++i)
        s+=(x[i]*y[i+1]-x[i+1]*y[i]);
    s+=(x[n]*y[1]-x[1]*y[n]);
    s/=2;
    g<<s;
    return 0;
}