Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:42:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[x].size(); ++ i) ^ user.cpp: In function ‘void read()’: user.cpp:19:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:22:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp:30:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^