Compilare: main.cpp: In function 'int main()': main.cpp:21:14: 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=0; i<st.length(); i++){ | ~^~~~~~~~~~~~ main.cpp:16:8: warning: unused variable 'n' [-Wunused-variable] 16 | int n, a, i, c, rand, cnt=1, J; | ^ main.cpp:16:11: warning: unused variable 'a' [-Wunused-variable] 16 | int n, a, i, c, rand, cnt=1, J; | ^ main.cpp:16:33: warning: unused variable 'J' [-Wunused-variable] 16 | int n, a, i, c, rand, cnt=1, J; | ^