copy-list-with-random-pointer

最新推荐文章于 2020-01-05 17:16:00 发布

原创最新推荐文章于 2020-01-05 17:16:00 发布 · 184 阅读

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#算法 python #链表

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本文介绍了一种带有随机指针的复杂链表结构，并提供了一个实现深拷贝该链表的方法。通过在原有链表中插入新节点并调整指针的方式完成复制，确保了新旧链表完全独立。

A linked list is given such that each node contains an additional random pointer which could point to any node in the list or null.

Return a deep copy of the list.

class Node(object):
   def __init__(self, val, p=None, r=None):
      self.data = val
      self.next = p
      self.random = r

def Creatlist(n):
   if n <= 0:
      return False
   if n == 1:
      return Node(1)
   else:
      root = Node(1)
      tmp = root
      for i in range(2, n + 1):
         tmp.next = Node(i)
         tmp = tmp.next
   return root

def addRanodm(head):
   p = head
   while p.next and p.next.next:
      p.random = p.next.next
      p = p.next.next.next
   return head


def printlist(head):
   p = head
   while p != None:
      if p.random:
         print [p.data, p.random.data]
      else:
         print [p.data]
      p = p.next


class Solution(object):
   def copyList(self, head):
      if head is None:
         return head
      p = head
      while p is not None:
         newNode = Node(p.data)
         temp = p.next
         p.next = newNode
         newNode.next = temp
         p = temp
      p = head
      while p is not None:
         if p.random is not None:
            p.next.random = p.random.next
         p = p.next.next
      p = head
      newHead = head.next
      while p.next is not None:
         temp = p.next
         p.next = p.next.next
         p = temp
      return newHead

head = addRanodm(Creatlist(8))
printlist(head)
print "-------------------------"
P = Solution()
newhead = P.copyList(head)
printlist(newhead)