Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:17:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<adj[u].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:52:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("amici2.in","r",stdin); ^ user.cpp:53:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("amici2.out","w",stdout); ^ user.cpp:55:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&test); ^ user.cpp:59:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:63:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&u,&v); ^ user.cpp:77:13: warning: ‘res’ may be used uninitialized in this function [-Wmaybe-uninitialized] d[i]=res; ^ user.cpp:82:13: warning: ‘start’ may be used uninitialized in this function [-Wmaybe-uninitialized] bfs(start); ^