Python宝典第五章：数据结构与算法

<span style="font-size:14px;"># -*- coding:utf-8 -*-
# file: pystack.py
#
class PyStack:
def __init__(self, size = 20):
self.stack=[]
self.size=size
self.top=-1
def setSize(self, size):
self.size=size
def push(self, element):
if self.isFull():
raise StackException("PyStackOverFlow")
else:
self.stack.append(element)
self.top=self.top+1
def pop(self):
if self.isEmpty():
raise StackException("PyStackUnderFlow")
else:
element = self.stack[-1]
self.top=self.top-1
del self.stack[-1]
return element
def Top(self):
return self.top
def empty(self):
self.stack=[]
self.top=-1
def isEmpty(self):
if self.top==-1:
return True
else:
return False
def isFull(self):
if self.top==self.size-1:
return True
else:
return False

class StackException(Exception):
def __init__(self,data):
self.data=data
def __str__(self):
return self.data

if __name__=="__main__":
stack=PyStack()
for i in range(10):
stack.push(i)
print(stack.Top())
for i in range(10):
print(stack.pop())
stack.empty()</span>

# -*- coding:utf-8 -*-
# file: pyqueue.py
#
class PyQueue:
def __init__(self,size=20):
self.queue=[]
self.size=size
self.end=-1
def setSize(self, size):
self.size=size
def In(self, element):
if self.end<self.size-1:
self.queue.append(element)
self.end=self.end+1
else:
raise QueueException("PyQueueFull")
def Out(self):
if self.end !=-1:
element=self.queue[0]
self.queue=self.queue[1:]
self.end=self.end-1
return element
else:
raise QueueException("PyQueueEmpty")
def End(self):
return self.end
def empty(self):
self.queue=[]
self.end=-1

class QueueException(Exception):
def __init__(self,data):
self.data=data
def __str__(self):
return self. data

if __name__=="__main__":
queue=PyQueue()
for i in range(10):
queue.In(i)
#print(i)
print(queue.End())
for i in range(10):
#queue.Out();
print(queue.Out())
for i in range(20):
queue.In(i)
queue.empty()

# -*- coding:utf-8 -*-
# file: pybtree.py
#
class BTree:
def __init__(self, value):
self.left=None
self.data=value
self.right=None
def insertLeft(self, value):
self.left=BTree(value)
return self.left
def insertRight(self, value):
self.right=BTree(value)
return self.right
def show(self):
print(self.data)
def preorder(node):
if node.data:
node.show()
if node.left:
preorder(node.left)
if node.right:
preorder(node.right)
def inorder(node):
if node.data:
if node.left:
inorder(node.left)
node.show()
if node.right:
inorder(node.right)
def postorder(node):
if node.data:
if node.left:
postorder(node.left)
if node.right:
postorder(node.right)
node.show()
if __name__=="__main__":
Root=BTree("Root")
A=Root.insertLeft("A")
C=A.insertLeft("C")
D=A.insertRight("D")
F=D.insertLeft("F")
G=D.insertRight("G")
B=Root.insertRight("B")
E=B.insertRight("E")
print("***********************")
preorder(Root)
print("***********************")
inorder(Root)
print("***********************")
postorder(Root)

# -*- coding:utf-8 -*-
# file: pygraph.py
#
def generatePath(graph, path, end, results):
state=path[-1]
if state==end:
results.append(path)
else:
for arc in graph[state]:
if arc not in path:
generatePath(graph, path+[arc], end, results)
def searchGraph(graph, start, end):
results=[]
generatePath(graph, [start], end, results)
results.sort(key=lambda x:len(x))
return results
if __name__=="__main__":
Graph={ "A": ["B", "C" , "D"],
"B": ["E"],
"C": ["D", "F"],
"D": ["B", "E", "G"],
"E": [],
"F": ["D", "G"],
"G": ["E"]}
r=searchGraph(Graph, "A", "D")
for i in r:
print(i)

# -*- coding:utf-8 -*-
# file: pyBinarySearh.py
#
def BinarySearch(l, key):
low=0
high=len(l)-1
i=0
while(low<=high):
i=i+1
mid=(low+high)//2
if (l[mid]>key):
high=mid-1
elif (l[mid]<key):
low=mid+1
else:
print("use %d time(s)" % i)
return mid
return -1
if __name__=="__main__":
l=[1,5,6,9,10,51,62,65,70]
print(BinarySearch(l,65))

# -*- coding:utf-8 -*-
# file: pySort.py
#
class BTree:
def __init__(self, value):
self.left=None
self.data=value
self.right=None
def insertLeft(self, value):
self.left=BTree(value)
return self.left
def insertRight(self, value):
self.right=BTree(value)
return self.right
def show(self):
print(self.data)
def inorder(node):
if node.data:
if node.left:
inorder(node.left)
node.show()
if node.right:
inorder(node.right)
def rinorder(node):
if node.data:
if node.right:
rinorder(node.right)
node.show()
if node.left:
rinorder(node.left)
def insert(node, value):
if value > node.data:
if node.right:
insert(node.right, value)
else:
node.insertRight(value)
else:
if node.left:
insert(node.left, value)
else:
node.insertLeft(value)
if __name__=="__main__":
l=[3,5,7,20,43,2,15,30]
Root=BTree(l[0])
for i in range(1, len(l)):
insert(Root, l[i])
inorder(Root)
print("**********************")
rinorder(Root)