Compilare: user.cpp: In function 'void print(std::vector<int, std::allocator<int> >)': user.cpp:37: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'std::vector<int, std::allocator<int> > eval(char*, int, int)': user.cpp:82: warning: comparison between signed and unsigned integer expressions user.cpp:89: warning: comparison between signed and unsigned integer expressions user.cpp:96: warning: comparison between signed and unsigned integer expressions user.cpp:102: warning: comparison between signed and unsigned integer expressions user.cpp: In function 'int main()': user.cpp:127: warning: comparison between signed and unsigned integer expressions /tmp/cc7HXzim.o: In function `main': user.cpp:(.text+0xc1f): warning: the `gets' function is dangerous and should not be used.