Compilare: user.cpp: In function ‘int rec()’: user.cpp:93:65: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define re(II, NN) for (int II(0), _NN(NN); (II) < (NN); ++(II)) ^ user.cpp:151:3: note: in expansion of macro ‘re’ re (i, cur.size()) { ^ user.cpp:152:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i <= cur.size() - 1) { // not last son ^ user.cpp:93:46: warning: unused variable ‘_NN’ [-Wunused-variable] #define re(II, NN) for (int II(0), _NN(NN); (II) < (NN); ++(II)) ^ user.cpp:151:3: note: in expansion of macro ‘re’ re (i, cur.size()) { ^ user.cpp: In function ‘int expect(char)’: user.cpp:114:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ /tmp/ccWZejp3.o: In function `main': user.cpp:(.text.startup+0x72): warning: the `gets' function is dangerous and should not be used.