Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:13:25: error: expected primary-expression before ‘;’ token for (int i = 1; i <=; n ++) fin >> V[i].first >> V[i].second; ^ user.cpp:15:40: error: no match for ‘operator+=’ (operand types are ‘std::pair<double, double>’ and ‘double’) for (int i = 1; i <= n; i ++) V[0] += (V[i].first * V[i + 1].second - V[i].second * V[i + 1].first); ^ user.cpp:16:18: error: no match for ‘operator/’ (operand types are ‘std::pair<double, double>’ and ‘int’) fout << V[0] / 2 << '\n'; ^