Compilare: main.cpp: In function 'int main()': main.cpp:15:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1;i<s2.size();i++) ~^~~~~~~~~~ main.cpp:21:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i+z[i]<s2.size()&&s2[i+z[i]]==s2[z[i]]) ~~~~~~^~~~~~~~~~ main.cpp:30:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (z[i]==s.size()) ~~~~^~~~~~~~~~