Compilare: main.cpp: In function 'void z_function()': main.cpp:13:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 13 | for(int i=1;i<S.size();i++) | ~^~~~~~~~~ main.cpp:20:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 20 | while(i+z[i]<S.size()&&S[z[i]]==S[i+z[i]]) | ~~~~~~^~~~~~~~~ main.cpp:15:14: warning: variable 'ok' set but not used [-Wunused-but-set-variable] 15 | bool ok=0; | ^~ main.cpp: In function 'int main()': main.cpp:36:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | for(int i=0;i<S.size();i++) | ~^~~~~~~~~ main.cpp:37:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 37 | if(z[i]==A.size()) | ~~~~^~~~~~~~~~