Compilare: user.cpp: In function ‘int main()’: user.cpp:28:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0;i < a.size(); ++i) ^ user.cpp:31:90: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s.size() && s.top() < a[i] - '0' && tocut && s.size() + a.size() - i > M) ^ user.cpp:35:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(s.size() != M)s.pop(); ^