Compilare: user.cpp: In function ‘void build_Z_array(int*)’: user.cpp:22:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < str.size(); ++i) ^ user.cpp:27:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(R < str.size() && str[R - L] == str[R]) ^ user.cpp:41:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(R < str.size() && str[R - L] == str[R]) ^ user.cpp: In function ‘int main()’: user.cpp:60:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(period.size() < N) ^ user.cpp:90:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = M; i < str.size(); ++i) ^