Compilare: main.cpp: In function 'void insertst(std::string)': main.cpp:49:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 49 | for(int i=0;i<s.size();i++) | ~^~~~~~~~~ main.cpp: In function 'void delst(std::string)': main.cpp:68:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 68 | for(int i=0;i<s.size();i++) | ~^~~~~~~~~ main.cpp: In function 'void printst(std::string)': main.cpp:94:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 94 | for(int i=0;i<s.size();i++) | ~^~~~~~~~~ main.cpp: In function 'void printpref(std::string)': main.cpp:110:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 110 | for(int i=0;i<s.size();i++) | ~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:140:9: warning: unused variable 't' [-Wunused-variable] 140 | int t=1; | ^