Cod sursa(job #2514461)

Utilizator bogdanc2002Bogdan Colta bogdanc2002 Data 25 decembrie 2019 21:56:10
Problema Aria Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include<bits/stdc++.h>

using namespace std;
ifstream fin("aria.in");ofstream fout("aria.out");
int main(){
int long n;cin>>n;
long double a,b,x1,x2,y1,y2;long double aria=0;fin>>x1>>y1;a=x1;b=y1;
for(int a=1;a<n;a++){
    fin>>x2>>y2;
    aria+=x1*y2-x2*y1;
    x1=x2;y1=y2;
}
aria+=x1*b-a*y1;aria/=2;fout<<aria;

return 0;
}