message.cpp: In function 'void send(int&, std::vector<int>&, std::vector<bool>)':
message.cpp:21:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |         for(int i=0;i<kn.size();i++) {
      |                     ~^~~~~~~~~~
message.cpp:25:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |             cur[kn[i]] = (ind+i < sent.size() ? sent[ind+i] : 0);
      |                           ~~~~~~^~~~~~~~~~~~~
message.cpp: In function 'void send_message(std::vector<bool>, std::vector<bool>)':
message.cpp:36:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     for(int i=0;i<positions.size();i++)
      |                 ~^~~~~~~~~~~~~~~~~
message.cpp:40:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |     for(int i=0;i<message.size();i++)  sent.push_back(message[i]);
      |                 ~^~~~~~~~~~~~~~~
message.cpp:43:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |     while(ind<sent.size()) {
      |           ~~~^~~~~~~~~~~~
message.cpp: In function 'void receive(std::vector<int>&, std::vector<bool>&, std::vector<bool>)':
message.cpp:57:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |         for(int i=0;i<kn.size();i++) {
      |                     ~^~~~~~~~~~
message.cpp: In function 'std::vector<bool> receive_message(std::vector<std::vector<bool> >)':
message.cpp:70:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<bool> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   70 |     for(int i=0;i<received_bits.size();i++) receive(kn, msg, received_bits[i]);
      |                 ~^~~~~~~~~~~~~~~~~~~~~
message.cpp:74:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<bool>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   74 |     for(int i=POS+10;i<msg.size();i++) rel.push_back(msg[i]);
      |                      ~^~~~~~~~~~~
message.cpp:75:22: warning: comparison of integer expressions of different signedness: 'std::vector<bool>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   75 |     while(rel.size() > len) rel.pop_back();
      |           ~~~~~~~~~~~^~~~~