Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:16:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i != V[nod].size(); i ++){ ^ user.cpp:19:19: warning: NULL used in arithmetic [-Wpointer-arith] if(vec == NULL) ^ user.cpp: In function ‘int main()’: user.cpp:48:29: warning: passing NULL to non-pointer argument 1 of ‘void std::vector<_Tp, _Alloc>::resize(std::vector<_Tp, _Alloc>::size_type) [with _Tp = int; _Alloc = std::allocator<int>; std::vector<_Tp, _Alloc>::size_type = unsigned int]’ [-Wconversion-null] V[i].resize(NULL); ^ user.cpp:33:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zlego.in" , "r", stdin ); ^ user.cpp:34:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zlego.out", "w", stdout); ^ user.cpp:36:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &T); A[0] = ((1LL<<31)-1); ^ user.cpp:39:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:42:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &A[i]); ^ user.cpp:45:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &B[i]); ^