Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:33:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < V[n].size (); i++) ^ user.cpp: In function ‘void cit()’: user.cpp:15:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &N); ^ user.cpp:18:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &x, &y); ^ user.cpp:22:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("\n"); ^ user.cpp:25:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%c ", &S[i]); ^ user.cpp: In function ‘int main()’: user.cpp:106:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("arbpal.in", "r", stdin); ^ user.cpp:107:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("arbpal.out", "w", stdout); ^