Compilare: user.cpp: In function ‘void dijkstra()’: user.cpp:35:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a[k].size();i++){ ^ user.cpp: In function ‘void cit()’: user.cpp:15:38: 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:16:40: 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:17:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i",&n,&m); ^ user.cpp:19:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i%i",&i,&j,&w); ^