Compilare: main.cpp: In function 'int main()': main.cpp:25:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 25 | while (pos < stri.size()) { | ~~~~^~~~~~~~~~~~~ main.cpp:31:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | if (pos >= stri.size()) { | ~~~~^~~~~~~~~~~~~~ main.cpp:42:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 42 | if (pos >= stri.size()) { | ~~~~^~~~~~~~~~~~~~ main.cpp:47:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 47 | while (pos < stri.size() && '0' <= stri[pos] && stri[pos] <= '9') { | ~~~~^~~~~~~~~~~~~ main.cpp:50:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 50 | if (pos < stri.size() && stri[pos] == 'x') { | ~~~~^~~~~~~~~~~~~