Compilare: user.cpp: In function ‘void BFS(int)’: user.cpp:42:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘int main()’: user.cpp:53:11: warning: unused variable ‘f’ [-Wunused-variable] FILE *f = freopen("bfs.in", "r", stdin), ^ user.cpp:54:6: warning: unused variable ‘g’ [-Wunused-variable] *g = freopen("bfs.out", "w", stdout); ^ user.cpp:55:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &n, &m, &s); ^ user.cpp:57:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^