Compilare: main.cpp: In function 'void precalc_z(std::string&, std::string&)': main.cpp:14:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 14 | for(int i=1; i<s.size(); i++) | ~^~~~~~~~~ main.cpp:19:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 19 | while(r<s.size() && s[r-l]==s[r]) | ~^~~~~~~~~ main.cpp:31:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | while(r<s.size() && s[r-l]==s[r]) | ~^~~~~~~~~ main.cpp:42:19: 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=1; i<s.size(); i++) | ~^~~~~~~~~ main.cpp:47:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 47 | while(r<s.size() && s[r-l]==s[r]) | ~^~~~~~~~~ main.cpp:59:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 59 | while(r<s.size() && s[r-l]==s[r]) | ~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:76:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 76 | for(int i=b.size()-1; i<a.size(); i++) | ~^~~~~~~~~ main.cpp:85:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 85 | for(int i=1; i<=b.size()/2; i++) | ~^~~~~~~~~~~~