Compilare: main.cpp: In function 'void add(std::string&)': main.cpp:28:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 28 | for(j = 0;j < s.size();j++){ | ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:34:11: warning: unused variable 'cur' [-Wunused-variable] 34 | int n,i,cur = 0,j; | ^~~ main.cpp:34:19: warning: unused variable 'j' [-Wunused-variable] 34 | int n,i,cur = 0,j; | ^