Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:59:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < V[x].size(); ++ i) ^ user.cpp:81:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < son.size(); ++ i) ^ user.cpp: In function ‘void read()’: user.cpp:40:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:43:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &c[i]); ^ user.cpp:47:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^