Cod sursa(job #2572627)
Utilizator | Vasile Andrei spartanul300 | Data | 5 martie 2020 13:36:58 |
---|---|---|---|
Problema | Aria | Scor | 70 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.51 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream f("aria.in");
ofstream g("aria.out");
struct
{
double x,y;
}v[100100];
double arie,px1,py1,px2,py2;
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++)
{
px1=v[i].x;py1=v[i].y;
if(i+1<=n)px2=v[i+1].x,py2=v[i+1].y;
else px2=v[1].x,py2=v[1].y;
arie+=(px1*py2-py1*px2)/2;
}
g<<fixed<<setprecision(6)<<arie;
return 0;
}