(self, root)
| 12 | class Tranversal: |
| 13 | # preorder without recursion |
| 14 | def preOrder(self, root): |
| 15 | if root == None: |
| 16 | return None |
| 17 | pNode, treeStack = root, [] |
| 18 | while pNode or len(treeStack) > 0: |
| 19 | while pNode: |
| 20 | print(pNode.val) |
| 21 | treeStack.append(pNode) |
| 22 | pNode = pNode.left |
| 23 | if len(treeStack) > 0: |
| 24 | pNode = treeStack.pop() |
| 25 | pNode = pNode.right |
| 26 | # preorder with recursion |
| 27 | def preOrderRec(self, root): |
| 28 | if root != None: |