Compilare: user.cpp: In member function ‘void Dijkstra::CalculateMinDistances()’: user.cpp:43:67: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < edge_list_[best_node.second].size(); ++i) { ^ user.cpp: In function ‘int main()’: user.cpp:68:37: 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:69:39: 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:73:43: 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:78:62: 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); ^