Pagini recente » Borderou de evaluare (job #1357496) | Borderou de evaluare (job #2860851) | Borderou de evaluare (job #2039589) | Cod sursa (job #1242076) | Cod sursa (job #2039633)
#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;
ifstream f("aria.in");
ofstream c("aria.out");
int main()
{ long x[1000000],y[1000000],N;
double s=0;
f>>N;
for(int i=1;i<=N;i++)
f>>x[i]>>y[i];
x[N+1]=x[1];
y[N+1]=y[1];
for(int i=1;i<=N;i++)
s+=x[i]*y[i+1]-x[i+1]*y[i];
c<<setprecision(5)<<fixed<<s/2;
}