answer.code:6:1: error: ‘vector’ does not name a type
    6 | vector<bool> send_packet(vector<bool> x) {
      | ^~~~~~
answer.code:14:6: error: variable or field ‘send_message’ declared void
   14 | void send_message(vector<bool> inpt, vector<bool> ctrl) {
      |      ^~~~~~~~~~~~
answer.code:14:19: error: ‘vector’ was not declared in this scope
   14 | void send_message(vector<bool> inpt, vector<bool> ctrl) {
      |                   ^~~~~~
answer.code:2:1: note: ‘std::vector’ is defined in header ‘<vector>’; did you forget to ‘#include <vector>’?
    1 | #include<iostream>
  +++ |+#include <vector>
    2 | using namespace std;
answer.code:14:26: error: expected primary-expression before ‘bool’
   14 | void send_message(vector<bool> inpt, vector<bool> ctrl) {
      |                          ^~~~
answer.code:14:38: error: ‘vector’ was not declared in this scope
   14 | void send_message(vector<bool> inpt, vector<bool> ctrl) {
      |                                      ^~~~~~
answer.code:14:38: note: ‘std::vector’ is defined in header ‘<vector>’; did you forget to ‘#include <vector>’?
answer.code:14:45: error: expected primary-expression before ‘bool’
   14 | void send_message(vector<bool> inpt, vector<bool> ctrl) {
      |                                             ^~~~
answer.code:48:1: error: ‘vector’ does not name a type
   48 | vector<bool> recieve_message(vector<vector<bool> > inpt) {
      | ^~~~~~
stub.cpp: In function ‘int {anonymous}::sz(const C&)’:
stub.cpp:27:52: error: ‘size’ is not a member of ‘std’; did you mean ‘size_t’?
   27 | template<class C> int sz(const C& c) { return std::size(c); }
      |                                                    ^~~~
      |                                                    size_t
stub.cpp: In function ‘void {anonymous}::write_int_array(const int*, int)’:
stub.cpp:70:13: warning: init-statement in selection statements only available with ‘-std=c++17’ or ‘-std=gnu++17’
   70 |         if (int ret = fwrite(arr, sizeof(int), len, fout); len != ret) {
      |             ^~~
stub.cpp: In function ‘void {anonymous}::read_int_array(int*, int)’:
stub.cpp:105:13: warning: init-statement in selection statements only available with ‘-std=c++17’ or ‘-std=gnu++17’
  105 |         if (int ret = fread(arr, sizeof(int), len, fin); len != ret) {
      |             ^~~