Compilare: user.cpp: In member function ‘void MinHeap::Debug()’: user.cpp:28:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < nodes_.size(); ++i) { ^ user.cpp: In member function ‘int MinHeap::Push(int, int)’: user.cpp:41:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In member function ‘void MinHeap::Down(int)’: user.cpp:72:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (position < nodes_.size()) { ^ user.cpp:76:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (right_sub_node < nodes_.size() && nodes_[right_sub_node].second < nodes_[left_sub_node].second) { ^ user.cpp:79:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (best_chose < nodes_.size()) { ^ user.cpp: In member function ‘void Dijkstra::CalculateMinDistances()’: user.cpp:107:60: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < edge_list_[best_node].size(); ++i) { ^ user.cpp: In member function ‘std::vector<int> Dijkstra::GetDistances()’: user.cpp:121:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < distances.size(); ++i) { ^ user.cpp: In function ‘int main()’: user.cpp:137:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra.in","r",stdin); ^ user.cpp:138:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dijkstra.out","w",stdout); ^ user.cpp:142:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &num_nodes, &num_edges); ^ user.cpp:147:62: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &start_node, &end_node, &edge_cost); ^