Compilare: main.cpp: In function 'bool as(std::string, std::string)': main.cpp:15:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 15 | for(int x=0;x<a.length();x++) v[x]=0; | ~^~~~~~~~~~~ main.cpp:16:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 16 | for(int x=0;x<a.length();x++) | ~^~~~~~~~~~~