Cod sursa(job #1921912)
Utilizator | bogdan bancuta bogdi1 | Data | 10 martie 2017 15:20:51 |
---|---|---|---|
Problema | Aria | Scor | 10 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.43 kb |
#include <cstdio>
using namespace std;
const int eps = 1.e-14;
int main()
{ freopen("aria.in", "r",stdin);
freopen("aria.out", "w",stdout);
double x1,y1,x2,y2,a;
int i,n;
scanf("%d", &n);
scanf("%lf%lf", &x1, &y1);
for(i=2; i<=n;i++){
scanf("%lf%lf", &x2, &y2);
a+=(x1-x2)*(y1+y2);
x1=x2;
y1=y2;
}
a/=2;
if(a<eps)
a*=-1;
printf("%.5lf", a);
return 0;
}