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?
Note:
- 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
原题链接：https://oj.leetcode.com/problems/populating-next-right-pointers-in-each-node-ii/
题目：前一题的继续。假设给定的是随意的二叉树。前题的代码还能用吗？
思路：显然，前一题不能用了。仅仅好用层序遍历。
public void connect(TreeLinkNode root) {
if(root == null)
return;
TreeLinkNode parent = root,pre,next;
while(parent != null){
pre = null;
next = null;
while(parent != null){
if(next == null)
next = (parent.left == null) ? parent.right : parent.left;
if(parent.left != null){
if(pre != null){
pre.next = parent.left;
pre = pre.next;
}else
pre = parent.left;
}
if(parent.right != null){
if(pre != null){
pre.next = parent.right;
pre = pre.next;
}else
pre = parent.right;
}
parent = parent.next;
}
parent = next;
}
}