Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:15:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[nod].size();i++) { ^ user.cpp:20:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[nod].size();i++) ^ user.cpp:26:28: 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:33:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dosare.in","r",stdin); ^ user.cpp:34:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dosare.out","w",stdout); ^ user.cpp:35:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:37:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&j); ^ user.cpp:41:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&k[i]); ^