#二叉樹的插入,尋找。如果有就不用插入,如果沒有就插入
class tree:
def __init__(self):
self.data=0
self.left=None
self.right=None
def create_tree(root,val):
newnode=tree()
newnode.data=val
if root==None:
root=newnode
return root
else:
current=root
while current!=None:
backup=current
if current.data>val:
current=current.left
else:
current=current.right
if backup.data>val:
backup.left=newnode
else:
backup.right=newnode
return root
def search(ptr,data):#先查找有沒有,,沒有的話再插入
i = 1
while True:
if ptr==None:
return ptr
if ptr.data==data:
print('通過[%d]次找到'%i)
return ptr
elif ptr.data>data:
ptr=ptr.left
else:
ptr=ptr.right
i+=1
def midorder(ptr):#中序遍歷
if ptr!=None:
midorder(ptr.left)
print('中序法排序爲%d'%ptr.data)
midorder(ptr.right)
data=[7,1,4,2,8,13,12,11,15,9,5]
ptr=None
lookfor=13
for i in range(len(data)):
ptr=create_tree(ptr,data[i])
result=search(ptr,lookfor)
if result==None:
print('沒有找到')
ptr = create_tree(ptr, lookfor)
else:
print("不用插入")
midorder(ptr)
參考圖解數據結構書