按正序和反序输入线性表各数据元素的值,建立两个有序链表。并将两个有序表合并为一个有序表
时间: 2023-05-01 13:03:42 浏览: 99
题目大意:按正序和反序输入线性表各数据元素的值,建立两个有序链表,并将两个有序表合并为一个有序表。
解析:题目要求我们建立两个有序链表,一个是正序的,一个是反序的,这就需要我们要对输入的数据元素进行区分。然后,我们可以使用链表的插入操作将数据元素插入有序链表中,使得有序链表维持有序的状态。最后,我们只需要将两个有序链表合并为一个有序链表,就可以得到答案了。
相关问题
用python将二叉搜索树转换为双向循环链表,防止循环输出,再分别按正序和反序输出链表元素
好的,我来回答你的问题。
下面是将二叉搜索树转换为双向循环链表的Python代码:
```python
class Node:
def __init__(self, val=None, left=None, right=None):
self.val = val
self.left = left
self.right = right
def treeToDoublyList(root: Node) -> Node:
if not root:
return None
def dfs(node):
if not node:
return
dfs(node.left)
if dfs.prev:
dfs.prev.right = node
node.left = dfs.prev
else:
dfs.head = node
dfs.prev = node
dfs(node.right)
dfs.prev = None
dfs.head = None
dfs(root)
dfs.head.left = dfs.prev
dfs.prev.right = dfs.head
return dfs.head
```
接下来,我们可以分别按正序和反序输出链表元素,如下:
```python
def printList(head: Node):
if not head:
return
curr = head
while curr:
print(curr.val, end=' ')
curr = curr.right
if curr == head:
break
def printListReverse(head: Node):
if not head:
return
curr = head.left
while curr:
print(curr.val, end=' ')
curr = curr.left
if curr == head.left:
break
```
完整的代码如下:
```python
class Node:
def __init__(self, val=None, left=None, right=None):
self.val = val
self.left = left
self.right = right
def treeToDoublyList(root: Node) -> Node:
if not root:
return None
def dfs(node):
if not node:
return
dfs(node.left)
if dfs.prev:
dfs.prev.right = node
node.left = dfs.prev
else:
dfs.head = node
dfs.prev = node
dfs(node.right)
dfs.prev = None
dfs.head = None
dfs(root)
dfs.head.left = dfs.prev
dfs.prev.right = dfs.head
return dfs.head
def printList(head: Node):
if not head:
return
curr = head
while curr:
print(curr.val, end=' ')
curr = curr.right
if curr == head:
break
def printListReverse(head: Node):
if not head:
return
curr = head.left
while curr:
print(curr.val, end=' ')
curr = curr.left
if curr == head.left:
break
# 测试代码
root = Node(4)
root.left = Node(2)
root.right = Node(5)
root.left.left = Node(1)
root.left.right = Node(3)
head = treeToDoublyList(root)
printList(head) # 1 2 3 4 5
print()
printListReverse(head) # 5 4 3 2 1
print()
```
希望能够帮助到你!
已知有一个链表,任意输入一个值,实现链表的顺序插入及链表反序。
好的,可以通过以下代码实现链表的顺序插入和反序:
```python
# 定义链表节点类
class ListNode:
def __init__(self, val=0, next=None):
self.val = val
self.next = next
# 定义链表类
class LinkedList:
def __init__(self):
self.head = None
# 链表的顺序插入
def insert(self, val):
node = ListNode(val)
if not self.head:
self.head = node
else:
curr = self.head
while curr.next:
curr = curr.next
curr.next = node
# 链表的反序
def reverse(self):
prev = None
curr = self.head
while curr:
next_node = curr.next
curr.next = prev
prev = curr
curr = next_node
self.head = prev
```
对于链表的顺序插入,我们可以先判断链表是否为空,如果为空,则将新节点设置为链表的头节点;如果不为空,则遍历整个链表,找到最后一个节点,将其的next指向新节点。
对于链表的反序,我们可以使用三个指针prev, curr和next_node,将curr指向的节点的next指向prev,然后将prev和curr都向后移动一个节点,直到curr变为None为止。最后将链表的头节点指向prev即可。