Cod sursa(job #2221789)

Utilizator inquisitorAnders inquisitor Data 15 iulie 2018 20:24:40
Problema Aria Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.24 kb
Raporteaza aceasta sursa 
#include <fstream>

std::ifstream f("aria.in");

main(){
    long double N,a,b,x,y,X,Y,S=0;
    f>>N>>a>>b;x=a;
    for(y=b;--N;S+=x*Y-X*y,x=X,y=Y)f>>X>>Y;

    S+=x*b-a*y;
    freopen("aria.out","w",stdout);printf("%.5LF",S/2);}