Compilare: main.cpp: In function 'void solve()': main.cpp:36:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | for(int i=2;i<v.size();i++){ | ~^~~~~~~~~ main.cpp:57:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 57 | for(int i=1;i<v.size();i++){ | ~^~~~~~~~~ main.cpp:35:10: warning: unused variable 'lastLetter' [-Wunused-variable] 35 | char lastLetter=v[1][0]; | ^~~~~~~~~~