Compilare: main.cpp: In function 'void evalExpDr()': main.cpp:84:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 84 | while (index < s.size()) | ~~~~~~^~~~~~~~~~ main.cpp: In function 'void termenDr()': main.cpp:102:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 102 | while (index < s.size() && '0' <= s[index] && s[index] <= '9') | ~~~~~~^~~~~~~~~~ main.cpp:108:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 108 | if (index < s.size() && s[index] == 'x') | ~~~~~~^~~~~~~~~~ main.cpp:125:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 125 | while (index < s.size() && '0' <= s[index] && s[index] <= '9') | ~~~~~~^~~~~~~~~~ main.cpp:131:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 131 | if (index < s.size() && s[index] == 'x') | ~~~~~~^~~~~~~~~~