Cod sursa(job #1696359)

Utilizator david12345Rotari David david12345 Data 28 aprilie 2016 22:35:08
Problema Aria Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include<fstream>
using namespace std;
ifstream fi("aria.in");
ofstream fo("aria.out");
struct p{
	int  x,y;
}v[100005];
int main(){
	int n,s;
	fi>>n;
	for(int i=1;i<=n;i++){
		fi>>v[i].x>>v[i].y;
	}
	v[n+1]=v[1];
	s=0;
	for(int i=1;i<=n;i++)
	   s+=(v[i].x*v[i+1].y-v[i+1].x*v[i].y);
	   fo<<s/2;
}