Cod sursa(job #1918789)

Utilizator FlorinHajaFlorin Gabriel Haja FlorinHaja Data 9 martie 2017 16:54:44
Problema Aria Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include<bits/stdc++.h>
using namespace std;
ifstream f("aria.in");
ofstream g("aria.out");
double x[100005], y[100005],sol;
int n,m,i;
int main() {
    for(f>>n,i=1;i<=n;i++)
        f>>x[i]>>y[i];
    for (i=1,x[n+1]=x[1],y[n+1]=y[1];i<=n;i++)
        sol+=(x[i]*y[i+1]-y[i]*x[i+1]);
    g<<fixed<<setprecision(5)<<fabs(sol)/2;
}