answer.code: In function ‘int main()’:
answer.code:12:5: error: ‘vector’ was not declared in this scope
   12 |     vector<long double> A(N);
      |     ^~~~~~
answer.code:3:1: note: ‘std::vector’ is defined in header ‘<vector>’; did you forget to ‘#include <vector>’?
    2 | #include <iomanip>
  +++ |+#include <vector>
    3 | 
answer.code:12:12: error: expected primary-expression before ‘long’
   12 |     vector<long double> A(N);
      |            ^~~~
answer.code:15:16: error: ‘A’ was not declared in this scope
   15 |         cin >> A[i];
      |                ^