Compilare: user.cpp: In function ‘void Read()’: user.cpp:19:9: warning: unused variable ‘i’ [-Wunused-variable] int i,m,x,y,cost; ^ user.cpp: In function ‘void Dijkstra()’: user.cpp:45:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<G[u].size();++i) ^ user.cpp: In function ‘void Read()’: user.cpp:21:37: 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:23:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:25:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&cost); ^ user.cpp: In function ‘void Write()’: user.cpp:63:39: 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); ^