我写了一个简单的函数来递归地反转链表。它返回更新的头指针

struct node* reverse(struct node *head)  
{  
static struct node *prev =NULL;  
if(head==NULL) return prev;  
struct node *q = head->next;  
head->next=prev;  
prev=head;  
return reverse(q);  
}    
struct node* reverse(struct node *head)  
{  
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