114. 二叉树展开为链表
114. 二叉树展开为链表
题目：
题解：
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode() {}
* TreeNode(int val) { this.val = val; }
* TreeNode(int val, TreeNode left, TreeNode right) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
class Solution {
public void flatten(TreeNode root) {
while(root != null) {
//左子树为null,直接考虑下一节点
if(root.left == null) {
root = root.right;
}
else {
//找到左子树最右边的结点
TreeNode pre = root.left;
while(pre.right != null) {
pre = pre.right;
}
//将原来的右子树接到左子树的最右边结点
pre.right = root.right;
root.right = root.left;
root.left = null;
root = root.right;
}
}
}
}