Compilare: user.cpp: In member function ‘void GRAPH::Dijkstra(int, std::vector<int>&)’: user.cpp:40:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<graph[nod.first].size(); i++) ^ user.cpp:50:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=2; i<dist.size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:58:39: 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:59:41: 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:61:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:68:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &a, &b, &c); ^