外卖网站开发背景semester
*n 一级指针：
| &n | n | *n |
| 自身地址 | 指向地址 | 指向地址值 |
**s 二级指针：
| &s | s | *s | **s |
| 自身地址 | 一级指针地址 | 一级指针指向地址 | 一级指针指向地址值 |
CHILD *walk, *next, *tmp_child, **scan;next = walk->next
scan = &walk->next;
while (*scan) { // *scan = walk->nextif (!tree_equal(walk->child, (*scan)->child)) { // (*scan)->child) = walk->next->childscan = &(*scan)->next; // &(*scan)->next = &walk->next->child} else {if (next == *scan) // (next == *scan) ==> (next == walk->next)next = (*scan)->next; // (*scan)->next = walk->next->nextcount++;tmp_child = (*scan)->next; // (*scan)->next = walk->next->nextfree(*scan);*scan = tmp_child; // *scan = walk->next}
}