Compilare: user.cpp: In function ‘void Dijkstra(int)’: user.cpp:36:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<v[k.first].size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:50:38: 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:51:40: 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:55:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d",&n,&m); ^ user.cpp:64:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d %d",&A,&B,&C); ^