优先级队列(python) 

 1 class PriorQueque:
 2     def __init__(self, list1=[]):
 3         self.__list = []
 4         self.__MakeMaxHeap(list1)
 5     
 6     def __HeapUp(self):
 7         curIndex = len(self.__list) - 1 #tail element
 8         parentIndex = (curIndex-1)//2
 9         while(parentIndex >= 0 and self.__list[curIndex] > self.__list[parentIndex]):
10             self.__list[curIndex], self.__list[parentIndex] = \
11             self.__list[parentIndex], self.__list[curIndex]
12             curIndex = parentIndex
13             parentIndex = (curIndex-1)//2
14         
15     def __HeapDown(self):
16         retValue = self.__list[0]
17         self.__list[0] = self.__list.pop()
18         disorderValue = self.__list[0]
19         lastIndex = len(self.__list) - 1
20         bigIndex = 0
21         curIndex = 0 
22         leftIndex = 2 * curIndex + 1 
23         while(leftIndex <= lastIndex):
24             bigIndex = leftIndex
25             if(leftIndex < lastIndex and self.__list[leftIndex] < self.__list[leftIndex + 1]):
26                 bigIndex = leftIndex + 1
27             if(disorderValue >= self.__list[bigIndex]):
28                 break
29             self.__list[curIndex] = self.__list[bigIndex]
30             curIndex = bigIndex
31             leftIndex = 2 * curIndex + 1
32         self.__list[curIndex] = disorderValue
33         return retValue
34 
35     def Pop(self):
36         if(len(self.__list) <= 2):
37             return self.__list.pop()
38         else:
39             return self.__HeapDown()
40     
41     def Push(self, value):
42         self.__list.append(value)
43         self.__HeapUp()
44 
45     def Top(self):
46         return self.__list[0]
47 
48     def __MakeMaxHeap(self, list1):
49         for i in list1:
50             self.Push(i)
51 
52     def __repr__(self):
53         return self.__list.__repr__()
54 
55 
56     
57

 

posted @ 2020-11-06 10:36  黑马网仔  阅读(153)  评论(0)    收藏  举报