import queue
"""
二叉搜索树：
特点：左子树的值小于根节点的值；右子树的值大于根节点的值
1.创建
2.插入节点
3.广度优先遍历
4.根据值查找节点
5.删除节点
"""
class TreeNode(object):
"""定义树的节点"""
def __init__(self, val):
self.value = val
self.father = None
self.left = None
self.right = None
class BinarySearchTree(object):
def __init__(self, nodeList):
"""构建二叉搜索树"""
self.root = None
for node in nodeList:
self.insert(node)
def insert(self, node):
"""插入节点"""
father = None
cur = self.root
# 找到要插入的位置
while cur is not None:
if cur.value == node.value:
return -1
father = cur
if node.value < cur.value:
cur = cur.left
else:
cur = cur.right
# 插入节点
node.father = father
if father is None:
# print("插入根节点")
self.root = node
elif node.value < father.value:
# print("插入左节点")
father.left = node
else:
# print("插入右节点")
father.right = node
def breadthFirstSearch(self):
"""广度优先遍历"""
if self.root is None:
return None
resultList = []
q = queue.Queue()
q.put(self.root)
while not q.empty():
node = q.get()
# print(node.value)
resultList.append(node.value)
if node.left is not None:
q.put(node.left)
if node.right is not None:
q.put(node.right)
return resultList
def search(self, value):
"""根据值查找节点"""
cur = self.root
while cur is not None:
if cur.value == value:
return cur
if value < cur.value:
cur = cur.left
if value > cur.value:
cur = cur.right
return None
def deleteNode(self, node):
"""删除节点"""
father = node.father
# 删除的节点没有左子树，右子树代替删除的节点
if node.left is None:
# 删除的节点是根节点
if father is None:
self.root = node.right
if node.right is not None:
node.right.father = None
# 删除的节点不是根节点
elif father.left == node: # 删除的节点是左子节点
father.left = node.right
if node.right is not None:
node.right.father = father
else: # 删除的节点是右子节点
father.right = node.right
if node.right is not None:
node.right.father = father
return 1
# 删除的节点有左子树，右子树挂到左子树的最右节点
tmpNode = node.left
while tmpNode.right is not None:
tmpNode = tmpNode.right
tmpNode.right = node.right
if node.right is not None:
node.right.father = tmpNode
# 删除的节点是根节点
if father is None:
self.root = node.left
node.left.father = None
# 删除的节点是左子节点
elif father.left == node:
father.left = node.left
node.left.father = father
# 删除的节点是右子节点
else:
father.right = node.left
node.left.father = father
# node=None
return 2
if __name__ == '__main__':
data = [24, 34, 5, 4, 8, 23, 45, 35, 28, 6, 29]
nodeList = [TreeNode(d) for d in data]
# 构建二叉搜索树
bst = BinarySearchTree(nodeList)
# 广度优先遍历
print(bst.breadthFirstSearch())
# 根据值查找节点
print(bst.search(23))
node = bst.search(8)
# 删除节点
bst.deleteNode(node)
print(bst.breadthFirstSearch())
