Compilare: main.cpp: In function 'int main()': main.cpp:16:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 16 | for( i = 1; i < a.size(); i++ ){ | ~~^~~~~~~~~~ main.cpp:20:33: 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] < a.size() && a[z[i]] == a[i + z[i]] ){ | ~~~~~~~~~^~~~~~~~~~