Compilare: main.cpp: In function 'int solve()': main.cpp:10:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 10 | while(poz < c.size()){ | ~~~~^~~~~~~~~~ main.cpp:18:46: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 18 | while(strchr("0123456789", x) && poz < c.size()){ | ~~~~^~~~~~~~~~