這只是一個非常簡單的代碼,我的參考就是從這裏開始:http://www.mathcs.emory.edu/~cheung/Courses/323/Syllabus/Map/skip-list-impl.html#why-q我想用Python實現一個跳過列表。你可以幫我嗎?很簡單
我想插入功能是好的,但是當我嘗試使用get()
功能,它不返回任何東西,而是循環無休止地在searchEntry()
部分內。我不知道什麼是錯的。在insert()
功能中,searchEntry()
運行良好。它返回對floorEntry(k)
條目的引用,其中包含的關鍵字小於需要在跳過列表中插入的關鍵字。請幫我弄清searchEntry()
函數中的錯誤來源。對不起,我並不擅長這一點。謝謝!
from QuadLinkedList import QLLNode
import random
class Skippy:
def __init__(self):
self._p1 = QLLNode("MINUS_INF")
self._p2 = QLLNode("PLUS_INF")
self._head = self._p1
self._tail = self._p2
self._p1.setNext(self._p2)
self._p2.setPrev(self._p1)
self._height = 0
self._n = 0
def insert(self, key, value):
p = self.searchEntry(key)
print "p = " + str(p.getKey())
q = QLLNode(key, value)
q.setPrev(p)
q.setNext(p.getNext())
p.getNext().setPrev(q)
p.setNext(q)
i = 0
while random.randint(0,1) != 0:
if i >= self._height:
self._height += 1
newHead = QLLNode("MINUS_INF")
newTail = QLLNode("PLUS_INF")
newHead.setNext(newTail)
newHead.setDown(self._head)
newTail.setPrev(newHead)
newTail.setDown(self._tail)
self._head.setUp(newHead)
self._tail.setUp(newTail)
self._head = newHead
self._tail = newTail
while p.getUp() == None:
p = p.getPrev()
p = p.getUp()
e = QLLNode(key,None)
e.setPrev(p)
e.setNext(p.getNext())
e.setDown(q)
p.getNext().setPrev(e)
p.setNext(e)
q.setUp(e)
q = e
i += 1
self._n += 1
return None
def get(self, key):
p = self.searchEntry(key)
if key == p.getKey():
return p.getElement()
else:
return "There's None!"
def searchEntry(self, key):
p = self._head
while True:
while p.getNext().getKey() != "PLUS_INF" and p.getNext().getKey() <= key:
p = p.getNext()
if p.getDown() != None:
p = p.getDown()
else:
break
return p
謝謝您的回答!根據您的建議編輯我的代碼。但是它仍然不返回get()部分中的任何內容。 – shedsomelight