Python3程序将链表的子列表从位置M到N向右旋转K位
给定一个链表和两个位置“m”和“n”。任务是将子列表从位置 m 旋转到 n,向右旋转 k 个位置。
例子:
Input: list = 1->2->3->4->5->6, m = 2, n = 5, k = 2
Output: 1->4->5->2->3->6
Rotate the sublist 2 3 4 5 towards right 2 times
then the modified list are: 1 4 5 2 3 6
Input: list = 20->45->32->34->22->28, m = 3, n = 6, k = 3
Output: 20->45->34->22->28->32
Rotate the sublist 32 34 22 28 towards right 3 times
then the modified list are: 20 45 34 22 28 32
方法:为了旋转从 m 到 n 元素的给定子列表,将列表从第 (n-k+1)个节点移动到第 n个节点到子列表的开头以完成旋转。
如果 k 大于子列表的大小,那么我们将取其与子列表大小的模数。因此,使用指针和计数器遍历列表,我们将保存第 (m-1)个节点,然后使其指向第 (n-k+1)个节点,从而将第 (n-k+1)个节点带到子列表的开始(前)。
同样,我们将保存第 m个节点,然后让第 n个节点指向它。为了保持列表的其余部分完好无损,我们将使 (nk) th节点指向 n 的下一个节点(可能为 NULL)。最后我们将得到 k 次右旋子列表。
下面是上述方法的实现:
Python3
# Python3 implementation of the above approach
import math
# Definition of node of linkedlist
class Node:
def __init__(self, data):
self.data = data
self.next = None
# This function take head pointer of list,
# start and end points of sublist that is
# to be rotated and the number k and
# rotate the sublist to right by k places.
def rotateSubList(A, m, n, k):
size = n - m + 1
# If k is greater than size of sublist then
# we will take its modulo with size of sublist
if (k > size):
k = k % size
# If k is zero or k is equal to size or k is
# a multiple of size of sublist then list
# remains intact
if (k == 0 or k == size):
head = A
while (head != None):
print(head.data)
head = head.next
return
link = None # m-th node
if (m == 1) :
link = A
# This loop will traverse all node till
# end node of sublist.
c = A # Current traversed node
count = 0 # Count of traversed nodes
end = None
pre = None # Previous of m-th node
while (c != None) :
count = count + 1
# We will save (m-1)th node and later
# make it point to (n-k+1)th node
if (count == m - 1) :
pre = c
link = c.next
if (count == n - k) :
if (m == 1) :
end = c
A = c.next
else :
end = c
# That is how we bring (n-k+1)th
# node to front of sublist.
pre.next = c.next
# This keeps rest part of list intact.
if (count == n) :
d = c.next
c.next = link
end.next = d
head = A
while (head != None) :
print(head.data, end = " ")
head = head.next
return
c = c.next
# Function for creating and linking new nodes
def push(head, val):
new_node = Node(val)
new_node.data = val
new_node.next = head
head = new_node
return head
# Driver code
if __name__=='__main__':
head = None
head = push(head, 70)
head = push(head, 60)
head = push(head, 50)
head = push(head, 40)
head = push(head, 30)
head = push(head, 20)
head = push(head, 10)
tmp = head
print("Given List: ", end = "")
while (tmp != None) :
print(tmp.data, end = " ")
tmp = tmp.next
print()
m = 3
n = 6
k = 2
print("After rotation of sublist: ", end = "")
rotateSubList(head, m, n, k)
# This code is contributed by Srathore
Given List: 10 20 30 40 50 60 70
After rotation of sublist: 10 20 50 60 30 40 70
请参阅完整文章将链表的子列表从位置 M 向右旋转 K 位以获取更多详细信息!