# For our current solution, it doesn't matter if the tree is perfect or not. # Definition for binary tree with next pointer. # class TreeLinkNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None # self.next = None class Solution: # @param root, a tree link node # @return nothing def connect(self, root): if root == None: return queue = [root] while len(queue) != 0: levelNum = len(queue) prev = None for i in range(levelNum): curNode = queue del queue curNode.next = prev prev = curNode if curNode.right: queue.append(curNode.right) if curNode.left: queue.append(curNode.left)
Follow up for problem "Populating Next Right Pointers in Each Node".
What if the given tree could be any binary tree? Would your previous solution still work?
You may only use constant extra space. For example, Given the following binary tree,
1 / \ 2 3 / \ \ 4 5 7
After calling your function, the tree should look like:
1 -> NULL / \ 2 -> 3 -> NULL / \ \ 4-> 5 -> 7 -> NULL