Cod sursa(job #2211438)
Utilizator | Data | 10 iunie 2018 12:24:56 | |
---|---|---|---|
Problema | Aria | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.48 kb |
#include <iostream>
#include <fstream>
#include <iomanip>
using namespace std;
ifstream in("aria.in");
ofstream out("aria.out");
struct vertex{
int x, y;
}a[100010];
double s;
int main(){
int n, i;
in >> n;
for(i = 1; i <= n; i++)
in >> a[i].x >> a[i].y;
a[n + 1] = a[1];
for(i = 1; i <= n; i++)
s += 0.5 * (a[i].x * a[i + 1].y - a[i].y * a[i + 1].x);
if(s < 0)
s = -s;
out << fixed << setprecision(5) << s;
return 0;
}