所以我在这个程序中遇到了一个小错误,但我真的不知道如何修复它,如果有人能帮助我指出它在哪里,我将非常感激。所以基本上,第一个函数将排序数组转换为平衡二叉搜索树,第二个函数返回给定节点的树的高度。当我编译该程序时,出现如下错误:
我试图打印出“aNode”对象来测试,我惊讶地发现它一开始指向一个 Node 对象,但后来又指向一个 Tree 对象(?),我真的很困惑,真的不知道不知道如何调试这个。非常感谢您的帮助。
class Node(object):
def __init__(self, data):
self.data = data
self.lChild = None
self.rChild = None
class Tree(object):
def __init__(self):
self.root = None
# create a balanced binary search tree from a sorted list
def create_tree (self, a_list):
if (len(a_list) <= 0): return None
mid = (len(a_list))//2 # find the mid value of the sorted array & make it root
self.root = Node(a_list[mid])
self.root.lChild = self.create_tree(a_list[:mid])
self.root.rChild = self.create_tree(a_list[mid+1:])
return self
def get_height (self, aNode):
if (aNode == None):
return -1
else:
print(aNode) # I DID MY TEST HERE WHERE IT FIRST PRINT "NODE OBJECT", BUT PRINT "TREE OBJECT" LATER AND CAUSE THE PROGRAM TO FAIL
rHeight = self.get_height(aNode.rChild)
lHeight = self.get_height(aNode.lChild)
return (1+rHeight) if rHeight > lHeight else (1+lHeight)
def main():
new_tree = Tree().create_tree([1,9,11,17])
new_tree.get_height(new_tree.root)
main()
非常感谢!
最佳答案
问题是您每次都用新节点覆盖 self.root 。因此,在递归调用中的每个级别,您都将使用新的空节点重置 Tree 对象的 self.root 。
对代码进行一些小的更改应该可以解决该问题。还在 main 中的 get_height() 调用中添加了一个打印,因为它只返回一个整数,并且您没有将其分配给任何东西。
class Node(object):
def __init__(self, data):
self.data = data
self.lChild = None
self.rChild = None
class Tree(object):
def __init__(self, a_list):
self.root = self.create_tree(a_list)
# create a balanced binary search tree from a sorted list
def create_tree (self, a_list):
if (len(a_list) <= 0): return None
mid = (len(a_list))//2
root = Node(a_list[mid])
root.lChild = self.create_tree(a_list[:mid])
root.rChild = self.create_tree(a_list[mid+1:])
return root
def get_height (self, aNode):
if (aNode == None):
return -1
else:
print(aNode)
rHeight = self.get_height(aNode.rChild)
lHeight = self.get_height(aNode.lChild)
return (1+rHeight) if rHeight > lHeight else (1+lHeight)
def main():
new_tree = Tree([1,9,11,17])
print(new_tree.get_height(new_tree.root))
关于python - 调试Python : Binary Search Tree (Objects bug),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/55876609/