Cod sursa(job #964375)
Utilizator | Cretu Bogdan reking | Data | 20 iunie 2013 19:08:03 |
---|---|---|---|
Problema | Aria | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.46 kb |
#include <iostream>
#include <fstream>
#include <math.h>
#include <iomanip>
using namespace std;
ifstream f("aria.in");
ofstream g("aria.out");
int main ()
{
long long n,i,x,y,x2,y2,a,b;
double arie=0;
f>>n;
f>>x>>y;
a=x;b=y;
for (i=2;i<=n;i++)
{
f>>x2>>y2;
arie=arie+x*y2-y*x2;
x=x2;
y=y2;
}
arie=arie+x*a-b*y;
arie=arie/2;
g<<fixed<<setprecision(5)<<fabs(arie);
}