/in/foo.cc: In function 'bool check(int, int, bool&)':
/in/foo.cc:28:25: warning: argument to 'sizeof' in 'void* memset(void*, int, size_t)' call is the same expression as the destination; did you mean to dereference it? [-Wsizeof-pointer-memaccess]
    memset(vis, 1, sizeof(vis));
                         ^