Compilare: user.cpp: In function ‘int main()’: user.cpp:79:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbxyz.in","r",stdin); ^ user.cpp:80:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbxyz.out","w",stdout); ^ user.cpp:81:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ user.cpp: In function ‘void rezolva()’: user.cpp:49:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&x,&y,&z); ^ user.cpp:58:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n1,&n2); ^ user.cpp: In function ‘int main()’: user.cpp:72:14: warning: ‘nod’ may be used uninitialized in this function [-Wmaybe-uninitialized] dfs2(nod); ^ user.cpp:47:11: note: ‘nod’ was declared here int i,nod; ^