Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:15:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(a.size()!=nr) ^ user.cpp:23:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(b.size()!=nr) ^ user.cpp:32:5: error: ‘c’ was not declared in this scope c="" ^ user.cpp:33:5: error: expected ‘;’ before ‘while’ while(s!=0) ^