Compilare: user.cpp: In constructor ‘PQueue::PQueue(std::vector<Nod>&, int)’: user.cpp:53:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (size_t i = 1; i <= N; i++) { ^ user.cpp: In member function ‘void PQueue::sieve(int)’: user.cpp:67:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (left_son < heap.size() && heap[minim] > heap[left_son]) { ^ user.cpp:71:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (right_son < heap.size() && heap[minim] > heap[right_son]) { ^