Compilare: main.cpp: In function 'void func(std::string, int, int)': main.cpp:10:21: 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 (st>=0&&dr<str.size()&&str[st]==str[dr]) | ~~^~~~~~~~~~~ main.cpp: In function 'int solve(std::string)': main.cpp:19:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 19 | for (int i=0;i<str.size();i++) | ~^~~~~~~~~~~