给定一颗二叉搜索树，请找到第k个节点
'''
中序遍历
'''
class TreeNode:
def __init__(self, x):
self.val = x
self.left = None
self.right = None
class KNode:
def KthNode(self, pRoot, k):
global result
result = []
middle = self.midorder(pRoot)
if k <= 0 or len(middle) < k:
return None
else:
return middle[k - 1]
def midorder(self, pRoot):
if not pRoot:
return []
self.midorder(pRoot.left)
result.append(pRoot)
self.midorder(pRoot.right)
return result
root = TreeNode(10)
left = TreeNode(6)
right = TreeNode(15)
root.left = left
root.right = right
left1 = TreeNode(11)
right1 = TreeNode(20)
right.left = left1
right.right = right1
print(KNode().KthNode(root, 4).val)15正文完