Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:53:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[x].size(); ++ i) ^ user.cpp:47:10: warning: unused variable ‘ok’ [-Wunused-variable] bool ok = false; ^ user.cpp: In function ‘void read()’: user.cpp:27:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:29:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i].time); ^ user.cpp:32:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp: In function ‘void queries()’: user.cpp:151:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &Q); ^ user.cpp:154:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &z); ^