Compilare: main.cpp: In function 'int main()': main.cpp:42:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 42 | for(int i = len ; i < s.size() ; i++) | ~~^~~~~~~~~~ main.cpp:45:54: warning: suggest parentheses around '-' inside '<<' [-Wparentheses] 45 | sum -= ( s[i - len] - 'a' ) * (1<<len-1) , sum *= 2, sum += ( s[i] - 'a') ; | ~~~^~ main.cpp:70:36: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 70 | while(s.size() < ind) | ~~~~~~~~~^~~~~