Cod sursa(job #2726274)
Utilizator | Data | 20 martie 2021 16:28:42 | |
---|---|---|---|
Problema | Aria | Scor | 10 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.49 kb |
#include <bits/stdc++.h>
#define X first
#define Y second
using namespace std;
ifstream fin("aria.in");
ofstream fout("aria.out");
pair<long double, long double> coord[100002];
int n;
int main()
{
fin >> n;
for(int i = 1; i <= n; i++)
fin >> coord[i].X >> coord[i].Y;
coord[n + 1] = coord[1];
long double sol = 0;
for(int i = 1; i <= n; i++)
sol += coord[i].X * coord[i + 1].Y - coord[i].Y * coord[i + 1].X;
sol = abs(sol) * 1 / 2;
fout << setprecision(5) << sol;
return 0;
}