Cod sursa(job #2701223)
Utilizator | Isciuc Iustin - Constantin Iustin01 | Data | 30 ianuarie 2021 10:31:05 |
---|---|---|---|
Problema | Aria | Scor | 50 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 0.46 kb |
#include <bits/stdc++.h>
#define MAX 250005
using namespace std;
ifstream in("aria.in");
ofstream out("aria.out");
pair < long double , long double > v[10005];
int n;
long double sum;
int main(){
in>>n;
for(int i = 1; i <= n; i++)
in>>v[i].first>>v[i].second;
v[n + 1] = v[1];
for(int i = 1; i <= n; i++)
sum += v[i].first * v[i + 1].second - v[i + 1].first * v[i].second;
out<<fixed<<setprecision(5)<<sum / 2.0;
}