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<b.size();i++) | ~^~~~~~~~~ main.cpp:17:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 17 | while(i+z[i]<b.size()&&b[z[i]]==b[i+z[i]]) | ~~~~~~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:35:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | for(int i=a.size();i<b.size();i++) | ~^~~~~~~~~ main.cpp:36:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | if(z[i]==a.size()) | ~~~~^~~~~~~~~~