Compilare: main.cpp: In function 'void z_algo(std::__cxx11::string, int*)': main.cpp:11:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<s.length();i++) ~^~~~~~~~~~~ main.cpp:17:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(r<s.length() && s[r]==s[r-i]) ~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:42:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=b.length()+1;i+b.length()-1 < end;i++) ~~~~~~~~~~~~~~~^~~~~ main.cpp:40:6: warning: unused variable 'ans' [-Wunused-variable] int ans=0; ^~~