Compilare: main.cpp: In function 'void add(int)': main.cpp:19:22: 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 l=start;l<s.size();l++){ | ~^~~~~~~~~ main.cpp: In function 'void check(int)': main.cpp:35:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | for(int l=start;l<s.size();l++){ | ~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:55:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 55 | for(j=0;j<s.size();j++) add(j); | ~^~~~~~~~~ main.cpp:60:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 60 | for(j=0;j<s.size();j++) check(j); | ~^~~~~~~~~