Compilare: user.cpp: In function ‘void readData()’: user.cpp:24:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:26:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int u, v; scanf("%d%d", &u, &v); ^ user.cpp: In function ‘void DFS(int)’: user.cpp:68:9: warning: ‘father’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(*it != father) { ^