Cod sursa(job #2790735)
Utilizator | Data | 29 octombrie 2021 13:50:48 | |
---|---|---|---|
Problema | Aria | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.36 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream f("aria.in");
ofstream g("aria.out");
int main()
{
int n,i;
long long x,y,x1,y1,x2,y2,s=0;
f>>n;
f>>x2>>y2;
x1=x2;
y1=y2;
for(i=2;i<=n;i++)
{
f>>x>>y;
s+=x1*y-x*y1;
x1=x;
y1=y;
}
s+=x1*y2-y1*x2;
g<<abs(s/2);
return 0;
}