Compilare: main.cpp: In function 'int main()': main.cpp:21:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | for(i=1; i<s.size(); i++) | ~^~~~~~~~~ main.cpp:39:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 39 | for(i=1; i<s.size(); i++) | ~^~~~~~~~~ main.cpp:14:12: warning: unused variable 'n' [-Wunused-variable] 14 | int i, n, res, k=0, cnt=0, cnt2=0; | ^ main.cpp:14:15: warning: unused variable 'res' [-Wunused-variable] 14 | int i, n, res, k=0, cnt=0, cnt2=0; | ^~~ main.cpp:16:10: warning: unused variable 'ch' [-Wunused-variable] 16 | char ch; | ^~