Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:12:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[nod].size();i++) ^ user.cpp:16:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:26:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] {freopen ("alpin.in","r",stdin); ^ user.cpp:27:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("alpin.out","w",stdout); ^ user.cpp:29:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:32:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&ma[i][j]); ^ user.cpp:54:11: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] while(vc[x]!=0) ^