题目:
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
解答:
public class Solution {
public void connect(TreeLinkNode root) {
//重点是记录current, head, prev这三个结点
TreeLinkNode curt = root;
TreeLinkNode head = null;
TreeLinkNode prev = null;
while (curt != null) {
while (curt != null) {
if (curt.left != null) {
if (prev != null) {
prev.next = curt.left;
} else {
head = curt.left;
}
prev = curt.left;
}
if (curt.right != null) {
if (prev != null) {
prev.next = curt.right;
} else {
head = curt.right;
}
prev = curt.right;
}
curt = curt.next;
}
curt = head;
head = null;
prev = null;
}
}
}
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