常用排序

一、几种排序的比较：

class TreeNode(object):
def __init__(self,data=0,left=0,right=0):
self.data = data
self.left = left
self.right = right

class BTree(object):
def __init__(self,root=0):
self.root = root

def preOrder(self,treenode):
if treenode is 0:
return
print(treenode.data)
self.preOrder(treenode.left)
self.preOrder(treenode.right)
def inOrder(self,treenode):
if treenode is 0:
return
self.inOrder(treenode.left)
print(treenode.data)
self.inOrder(treenode.right)

def postOrder(self,treenode):
if treenode is 0:
return
self.postOrder(treenode.left)
self.postOrder(treenode.right)
print(treenode.data)
if __name__ == '__main__':
n1  = TreeNode(data=1)
n2 = TreeNode(2,n1,0)
n3 = TreeNode(3)
n4 = TreeNode(4)
n5 = TreeNode(5,n3,n4)
n6 = TreeNode(6,n2,n5)
n7 = TreeNode(7,n6,0)
n8 = TreeNode(8)
root = TreeNode('root',n7,n8)

bt = BTree(root)
print("preOrder".center(50,'-'))
print(bt.preOrder(bt.root))

print("inOrder".center(50,'-'))
print (bt.inOrder(bt.root))

print("postOrder".center(50,'-'))
print (bt.postOrder(bt.root))