|
| 1 | +#!/usr/bin/env python |
| 2 | +# -*- coding:UTF-8 |
| 3 | +__author__='shenshijun' |
| 4 | + |
| 5 | + |
| 6 | +classFibonacciHeap(object): |
| 7 | +"""实现斐波那契堆,斐波那契堆在一些操作执行的时候负责度比较低，而其他操作的复杂度和普通的堆是一样的""" |
| 8 | + |
| 9 | +classNode(object): |
| 10 | +"""节点实现""" |
| 11 | + |
| 12 | +def__init__(self,key,parent=None,child=None,left=None,right=None): |
| 13 | +"""Constructor for """ |
| 14 | +self.key=key |
| 15 | +self.degree=0 |
| 16 | +self.mark=False |
| 17 | +self.parent=parent |
| 18 | +self.child=child |
| 19 | +self.left=leftorself |
| 20 | +self.right=rightorself |
| 21 | + |
| 22 | +def__str__(self): |
| 23 | +returnstr(self.key)+" : "+str(self.degree) |
| 24 | + |
| 25 | +def__init__(self,*argv): |
| 26 | +"""Constructor for """ |
| 27 | +self.__root=None |
| 28 | +self.__size=0 |
| 29 | +map(self.insert,argv) |
| 30 | + |
| 31 | +definsert(self,key): |
| 32 | +self.__size+=1 |
| 33 | +ifself.__rootisNone: |
| 34 | +self.__root=self.Node(key) |
| 35 | +else: |
| 36 | +new_node=self.Node(key,left=self.__root.left,right=self.__root) |
| 37 | +self.__root.left.right=new_node |
| 38 | +self.__root.left=new_node |
| 39 | +ifnew_node.key<self.__root.key: |
| 40 | +self.__root=new_node |
| 41 | + |
| 42 | +defextract_min(self): |
| 43 | +ifself.__rootisNone: |
| 44 | +returnNone |
| 45 | + |
| 46 | +result=self.__root |
| 47 | +self.__size-=1 |
| 48 | + |
| 49 | +# 首先把根节点的子节点全部移到根链表上 |
| 50 | +child=self.__root.child |
| 51 | +foriinxrange(0,self.__root.degree): |
| 52 | +next_node=child.right |
| 53 | +self.__root.left.right=child |
| 54 | +child.left=self.__root.left |
| 55 | +self.__root.left=child |
| 56 | +child.right=self.__root |
| 57 | +child.parent=None |
| 58 | +child=next_node |
| 59 | + |
| 60 | +# 移除根节点 |
| 61 | +self.__root.left.right=self.__root.right |
| 62 | +self.__root.right.left=self.__root.left |
| 63 | +ifself.__root.rightisself.__root: |
| 64 | +self.__root=None |
| 65 | +else: |
| 66 | +self.__root=self.__root.right |
| 67 | +self.__extract_consolidating() |
| 68 | + |
| 69 | +returnresult.key |
| 70 | + |
| 71 | +def__extract_consolidating(self): |
| 72 | +# 合并根链表 |
| 73 | +node_degrees= {} |
| 74 | +pass_root=False |
| 75 | +cur_node=self.__root |
| 76 | +after_merge=False |
| 77 | +next_node=None |
| 78 | +whilecur_nodeisnotself.__rootornotpass_rootorafter_merge: |
| 79 | +ifcur_node==self.__root: |
| 80 | +pass_root=True |
| 81 | + |
| 82 | +ifnotafter_merge: |
| 83 | +next_node=cur_node.right |
| 84 | + |
| 85 | +d=cur_node.degree |
| 86 | +ifdinnode_degrees: |
| 87 | +other_node=node_degrees[d] |
| 88 | +sm_node=cur_nodeifcur_node.key<=other_node.keyelseother_node |
| 89 | +bg_node=cur_nodeifcur_node.key>other_node.keyelseother_node |
| 90 | +# 把大的节点连接到小的节点上面,然后继续在sm_node上面循环，因为sm_node的度数发生了变化 |
| 91 | +self.__link_to(bg_node,sm_node) |
| 92 | +delnode_degrees[d] |
| 93 | +after_merge=True |
| 94 | +cur_node=sm_node |
| 95 | +else: |
| 96 | +after_merge=False |
| 97 | +node_degrees[d]=cur_node |
| 98 | +cur_node=next_node |
| 99 | + |
| 100 | +self.__root=None |
| 101 | + |
| 102 | +ford,nodeinnode_degrees.iteritems(): |
| 103 | +node.parent=None |
| 104 | +ifself.__rootisNone: |
| 105 | +self.__root=node |
| 106 | +self.__root.left=node |
| 107 | +self.__root.right=node |
| 108 | +else: |
| 109 | +node.left=self.__root.left |
| 110 | +node.right=self.__root |
| 111 | +self.__root.left.right=node |
| 112 | +self.__root.left=node |
| 113 | + |
| 114 | +ifself.__root.key>node.key: |
| 115 | +self.__root=node |
| 116 | + |
| 117 | +@staticmethod |
| 118 | +def__link_to(src,dest): |
| 119 | +""" |
| 120 | + bugfix: 不能把src从根链表移除,这样的话会破坏根链表，导致在__extract_consolidating中的while找不到退出条件 |
| 121 | + 我是为了避免重新创建根链表而把src从根链表中移除，这段注释只是为了提醒 |
| 122 | + :param src: |
| 123 | + :param dest: |
| 124 | + :return: |
| 125 | + """ |
| 126 | +src.mark=False |
| 127 | + |
| 128 | +dest_child=dest.child |
| 129 | +src.parent=dest |
| 130 | +ifdest_childisNone: |
| 131 | +dest.child=src |
| 132 | +src.left=src |
| 133 | +src.right=src |
| 134 | +else: |
| 135 | +src.left=dest_child.left |
| 136 | +dest_child.left.right=src |
| 137 | +dest_child.left=src |
| 138 | +src.right=dest_child |
| 139 | +dest.degree+=1 |
| 140 | + |
| 141 | +defunion(self,other): |
| 142 | +pass |
| 143 | + |
| 144 | +defmin(self): |
| 145 | +returnNoneifself.__rootisNoneelseself.__root.key |
| 146 | + |
| 147 | +defchange_key(self,node,new_key): |
| 148 | +pass |
| 149 | + |
| 150 | +def__len__(self): |
| 151 | +returnself.__size |
| 152 | + |
| 153 | +defdelete(self,node): |
| 154 | +self.change_key(node,float('-Inf')) |
| 155 | +self.extract_min() |
| 156 | + |
| 157 | + |
| 158 | +defmain(): |
| 159 | +test= ['O','J','S','Y','C','M','B','R','N','F','L','Z','U','Q','A','G','V','E','D','W','I', |
| 160 | +'H','T','K','X','P'] |
| 161 | + |
| 162 | +heap=FibonacciHeap(*test) |
| 163 | +foriinxrange(0,len(heap)): |
| 164 | +print(heap.extract_min()) |
| 165 | + |
| 166 | + |
| 167 | +if__name__=="__main__": |
| 168 | +main() |
