Compilare: main.cpp: In function 'void add(std::string)': main.cpp:18:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 18 | for (int i=0;i<s.size();i++){ | ~^~~~~~~~~ main.cpp: In function 'void del(std::string)': main.cpp:33:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 33 | for (int i=0;i<s.size();i++){ | ~^~~~~~~~~ main.cpp:36:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | if (i==s.size()-1){ | ~^~~~~~~~~~~~ main.cpp: In function 'int task2(std::string)': main.cpp:43:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 43 | for (i=0;i<s.size();i++){ | ~^~~~~~~~~ main.cpp: In function 'int task3(std::string)': main.cpp:52:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 52 | for (i=0;i<s.size();i++){ | ~^~~~~~~~~