我是 Python 的新程序员。这是我的代码,它给了我错误。我真的不知道如何解决它。
二叉树类:
class BinaryTree:
def __init__(self, data):
self.data=data
self.right=None
self.left=None
def inOrderTraversal(self, root):
if root == None:
pass
else:
self.inOrderTraversal(root.left)
print root.data,
self.inOrderTraversal(root.right)
def printOrder(self):
self.inOrderTraversal(self)
生成不同的所有不同的树
def generateAllDistinctTrees(array,start,end):
returnResultList=[]
if start>end or start<0 or end>=len(array):
return returnResultList.append(None)
if start==end:
treeNode = BinaryTree(array[start])
return returnResultList.append(treeNode)
for i in range(-1,end-start):
leftResult = generateAllDistinctTrees(array,start+1,start+1+i)
rightResult = generateAllDistinctTrees(array,start+2+i,end)
for left in leftResult:
for right in rightResult:
treeTemp = BinaryTree(array[start])
treeTemp.left = left
treeTemp.right = right
returnResultList.append(treeTemp)
return returnResultList
我也尝试过使用附加
def generateAllDistinctTrees(array,start,end):
returnResultList=[]
if start>end or start<0 or end>=len(array):
return returnResultList.append(None)
if start==end:
treeNode = BinaryTree(array[start])
return returnResultList.append(treeNode)
for i in range(-1,end-start):
leftResult=list()
rightResult=list()
leftResult.append(generateAllDistinctTrees(array,start+1,start+1+i))
rightResult.append(generateAllDistinctTrees(array,start+2+i,end))
for left in leftResult[0]:
for right in rightResult[0]:
treeTemp = BinaryTree(array[start])
treeTemp.left = left
treeTemp.right = right
returnResultList.append(treeTemp)
return returnResultList
主功能
if __name__ == '__main__':
preOrderData=[]
scan = raw_input("Enter Number:")
for i in range(0,int(scan)):
preOrderData=preOrderData + [i+1]
results = []
results.append(generateAllDistinctTrees(preOrderData,0,len(preOrderData)-1))
for eachObject in results[0]:
eachObject.printOrder()
我使用了这段代码的 Java 版本。它运行良好,没有任何错误。但是在python中,它会给我以下错误:
对于第一个版本,如果 generateAllDistinctTrees:
Traceback (most recent call last):
File "<stdin>", line 7, in <module>
File "<stdin>", line 10, in generateAllDistinctTrees
File "<stdin>", line 11, in generateAllDistinctTrees
TypeError: 'NoneType' object is not iterable
对于 generateAllDistinctTrees 的第二个版本:(使用附加一个)
Traceback (most recent call last):
File "<stdin>", line 7, in <module>
File "<stdin>", line 9, in generateAllDistinctTrees
NameError: global name 'leftResult' is not defined
提前致谢!!!
我在这里附上了我的屏幕截图!!