Compilare: main.cpp: In function 'void solve1()': main.cpp:35:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | for(int i = 0 ; i < s.size () ; ++ i) | ~~^~~~~~~~~~~ main.cpp: In function 'void build(Node*, Node*&)': main.cpp:62:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 62 | if (ind == s.size ()) | ~~~~^~~~~~~~~~~~