Cod sursa(job #1880411)

Utilizator BAC_AndreiBejinariu Andrei Catalin BAC_Andrei Data 15 februarie 2017 18:58:05
Problema Aria Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 0.34 kb
Raporteaza aceasta sursa 
#include <bits/stdc++.h>
using namespace std;
ifstream f("aria.in");
ofstream g("aria.out");
long double xs,ys,xc,yc,xv,yv,a;
int n;
int main()
{
    f>>n>>xs>>ys;
    for(xc=xs,yc=ys,n--;n;n--,xc=xv,yc=yv)
    {
        f>>xv>>yv;
        a+=xc*yv-xv*yc;
    }
    a+=xc*ys-xs*yc;
    if(a<0)a=-a;
    g<<a/2;
    return 0;
}