1.1 实现链表的逆序

为便于后续编写代码，将部分函数封装在节点和头节点的类中。

#%%
class LHead:
    def __init__(self):
        self.next = None
    
    def get_ordered_list(self): # 以列表形式打印顺序表
        order_list = []
        if self.next == None or self == None:
            return order_list
        else:
            cur = self.next
            while cur != None:
                order_list.append(cur.data)
                cur = cur.next
            return order_list
        
    def ordered_list_size(self): #获得链表长度
        
        return len(self.get_ordered_list())
    
    def create_ordered_list(self,size): #在新建头结点后面生成有序链表
        i = 0
        tmp = None
        cur = self
        ordered_list = []
         #构造单链表
        while i < size:
             tmp = LNode(i)
             tmp.next = None
             cur.next = tmp
             cur = tmp
             i += 1
        cur = self.next
        while cur != None:
            ordered_list.append(cur.data)
            cur = cur.next
        return ordered_list,self
    
#%%
class LNode:
    def __init__(self,data):
        self.data = data
        self.next = None
        

#%%
def reverse_list(head):
    if head == None or head.next == None:
        return None
    else:
        cur = head.next
        pre = head
        inext = cur.next
        cur.next = None
        pre = cur
        cur = inext
        while cur.next != None:
            inext = cur.next
            cur.next = pre
            pre = cur
#            cur = cur.next
            cur = inext
            
        cur.next = pre
        head.next = cur
    return head
            
            
#%%
head1 = LHead()
list1, head1 = head1.create_ordered_list(9)
print(list1)

head2 = reverse_list(head1)
list2 = head2.get_ordered_list()
print(list2)