Cod sursa(job #2572465)
Utilizator | Vasile Andrei spartanul300 | Data | 5 martie 2020 12:54:27 |
---|---|---|---|
Problema | Aria | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.5 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream f("aria.in");
ofstream g("aria.out");
struct
{
double x,y;
}v[100100];
double arie,x1,x2,y1,y2;
int n,i;
int main()
{
f>>n;
for(i=1;i<=n;i++)
{
f>>v[i].x>>v[i].y;
}
for(i=1;i<=n;i++)
{
x1=v[i].x;y1=v[i].y;
if(i+1<=n)x2=v[i+1].x,y2=v[i+1].y;
else x2=v[1].x,y2=v[1].y;
arie+=(x1*y2-y1*x2)/2;
}
g<<fixed<<setprecision(6)<<arie;
return 0;
}