Cod sursa(job #3219065)
Utilizator | Sasha Costea Sasha_12454 | Data | 29 martie 2024 20:43:17 |
---|---|---|---|
Problema | Aria | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.48 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream in ("aria.in");
ofstream out ("aria.out");
const int NMAX=100005;
int n;
double s;
struct punct
{
int x, y;
};
punct v[NMAX];
int main()
{
in>>n;
for(int i=1;i<=n;i++)
{
in>>v[i].x>>v[i].y;
}
v[n+1].x=v[1].x;
v[n+1].y=v[1].y;
for(int i=1;i<=n;i++)
{
s+=0.50000*((v[i].x*v[i+1].y)-(v[i+1].x*v[i].y));
}
out<<fixed<<setprecision(5)<<s;
return 0;
}