常用数据结构Python实现

二分查找

 1 #!/usr/bin/python
 2 # -*- coding: UTF-8 -*-
 3 # added by kangye, dependent on python27
 4
 5 def BinarySearch(l,key):
 6     low=0
 7     high=len(l)-1
 8     i=0
 9     while(low <= high):
10         i = i+1
11         mid = low + ((high-low)>>1)
12         if(l[mid] < key):
13             low = mid + 1
14         elif (l[mid] > key):
15             high = mid -1
16         else:
17             print "use %d times" % i
18             return mid
19     return -1
20
21 if __name__ == "__main__":
22     l=[1,4,5,6,7,8,9,44,333,2233]
23     print l
24     print BinarySearch(l,4)
25     print BinarySearch(l,44)
26     print BinarySearch(l,8)
27     print BinarySearch(l,2233)
28     print BinarySearch(l,77)

B树

 1 #!/usr/bin/python
 2 # -*- coding: UTF-8 -*-
 3 # added by kangye, dependent on python27
 4
 5 class BTree:
 6     def __init__(self,value):
 7         self.left=None
 8         self.data=value
 9         self.right=None
10
11     def insertLeft(self,value):
12         self.left=BTree(value)
13         return self.left
14
15     def insertRight(self,value):
16         self.right=BTree(value)
17         return self.right
18
19     def show(self):
20         print self.data
21
22 def preorder(node):
23     if node.data:
24         node.show()
25         if node.left:
26             preorder(node.left)
27         if node.right:
28             preorder(node.right)
29
30 def inorder(node):
31     if node.data:
32         if node.left:
33             inorder(node.left)
34         node.show()
35         if node.right:
36             inorder(node.right)
37
38 def postorder(node):
39     if node.data:
40         if node.left:
41              postorder(node.left)
42         if node.right:
43             postorder(node.right)
44         node.show()
45
46 if __name__ == "__main__":
47
48     Root=BTree("root")
49     A=Root.insertLeft("A")
50     C=A.insertLeft("C")
51     D=C.insertRight("D")
52     F=D.insertLeft("F")
53     G=D.insertRight("G")
54     B=Root.insertRight("B")
55     E=B.insertRight("E")
56
57     print "pre-traversal"
58     preorder(Root)
59
60     print "in-traversal"
61     inorder(Root)
62
63     print "post-traversal"
64     postorder(Root)
65
66         

图

 1 #!/usr/bin/python
 2 # -*- coding: UTF-8 -*-
 3 # added by kangye, dependent on python27
 4
 5 def searchGraph(graph,start,end):
 6     results=[]
 7     generatePath(graph,[start],end,results)
 8     results.sort(lambda x,y:cmp(len(x),len(y)))
 9     return results
10
11 def generatePath(graph,path,end,results):
12     state=path[-1]
13     if state == end:
14         results.append(path)
15     else:
16         for arc in graph[state]:
17             if arc not in path:
18                 generatePath(graph,path+[arc],end,results)
19
20
21 if __name__ == "__main__":
22         Graph={
23               ‘A‘:[‘B‘,‘C‘,‘D‘],
24               ‘B‘:[‘E‘],
25               ‘C‘:[‘D‘,‘F‘],
26               ‘D‘:[‘B‘,‘E‘,‘G‘],
27               ‘E‘:[],
28               ‘F‘:[‘D‘,‘G‘],
29               ‘G‘:[‘E‘]
30               }
31         r = searchGraph(Graph,‘A‘,‘D‘)
32         print "A to D"
33         for i in r:
34             print i
35
36         r=searchGraph(Graph,‘A‘,‘E‘)
37         print "A to E"
38         for i in r:
39             print i

队列

 1 #!/usr/bin/python
 2 # -*- coding: UTF-8 -*-
 3 # added by kangye, dependent on python27
 4
 5 class Queue:
 6     def __init__(self,size=20):
 7         self.queue=[]
 8         self.size=size
 9         self.end=-1
10
11     def setSize(self,size):
12         self.size=size
13
14     def In(self,element):
15         if self.end < self.size -1:
16             self.queue.append(element)
17             self.end = self.end + 1
18         else:
19             raise "QueueFull"
20
21     def Out(self):
22         if self.end != -1:
23             element = self.queue[0]
24             self.queue=self.queue[1:]
25             self.end = self.end-1
26             return element
27         else:
28             raise "QueueEmpty"
29
30     def End(self):
31         return self.end
32
33     def empty(self):
34         self.queue=[]
35         self.end=-1
36
37 if __name__ == "__main__":
38
39     queue=Queue()
40     for i in range(10):
41         queue.In(i)
42     print queue.End()
43
44     for i in range(10):
45         print queue.Out()
46
47             

栈

 1 #!/usr/bin/python
 2 # -*- coding: UTF-8 -*-
 3 # added by kangye, dependent on python27
 4
 5 class Stack:
 6     def __init__(self,size=20):
 7         self.stack= []
 8         self.size= size;
 9         self.top= -1
10
11     def setSize(self,size):
12         self.size=size;
13
14     def push(self,element):
15         if self.isFull():
16             raise "StackOverflow"
17         else:
18             self.stack.append(element)
19             self.top = self.top + 1
20
21     def pop(self):
22         if self.isEmpty():
23             raise "StackUnderflow"
24         else:
25             element=self.stack[-1]
26             self.top=self.top-1;
27             del self.stack[-1]
28             return element
29
30     def Top(self):
31         return self.top
32
33     def empty(self):
34         self.stack=[]
35         self.top=-1
36
37     def isEmpty(self):
38         if self.top == -1:
39             return True
40         else:
41             return False
42
43     def isFull(self):
44         if self.top == self.size-1:
45             return True
46         else:
47             return False
48
49 if  __name__ == "__main__":
50
51     stack=Stack()
52
53     for i in range(10):
54         stack.push(i)
55     print stack.Top()
56
57     for i in range(10):
58        print stack.pop()
59
60     stack.empty()
61     print stack.Top()
62
63