Compilare: user.cpp: In function ‘int dfs(int)’: user.cpp:14:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i < v[nod].size(); ++i) { ^ user.cpp:18:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:23:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerere.in","r",stdin); ^ user.cpp:24:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerere.out","w",stdout); ^ user.cpp:25:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:27:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &k[i]); ^ user.cpp:30:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^ user.cpp:39:13: warning: ‘nod’ may be used uninitialized in this function [-Wmaybe-uninitialized] dfs(nod); ^