Compilare: main.cpp: In function 'int main()': main.cpp:23:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < s.size(); ++i) { ~~^~~~~~~~~~ main.cpp:25:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i + z[i] < s.size() && s[i + z[i]] == s[z[i]]) { ~~~~~~~~~^~~~~~~~~~ main.cpp:31:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i + z[i] < s.size() && s[i + z[i]] == s[z[i]]) { ~~~~~~~~~^~~~~~~~~~ main.cpp:42:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < s.size(); ++i) { ~~^~~~~~~~~~ main.cpp:43:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(z[i] == a.size()) { ~~~~~^~~~~~~~~~~