Compilare: main.cpp: In function 'void evalExpDr()': main.cpp:77:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 77 | while (index < s.size()) | ~~~~~~^~~~~~~~~~ main.cpp: In function 'void termenDr()': main.cpp:92:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 92 | while (index < s.size() && '0' <= s[index] && s[index] <= '9') | ~~~~~~^~~~~~~~~~ main.cpp:98:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 98 | if (index < s.size() && s[index] == 'x') | ~~~~~~^~~~~~~~~~ main.cpp:112:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 112 | while (index < s.size() && '0' <= s[index] && s[index] <= '9') | ~~~~~~^~~~~~~~~~ main.cpp:118:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 118 | if (index < s.size() && s[index] == 'x') | ~~~~~~^~~~~~~~~~