题目描述
输入一棵二叉搜索树,将该二叉搜索树转换成一个排序的双向链表。要求不能创建任何新的结点,只能调整树中结点指针的指向。
题解
递归思想
/**
public class TreeNode {
int val = 0;
TreeNode left = null;
TreeNode right = null;
public TreeNode(int val) {
this.val = val;
}
}
*/
public class Solution {
public TreeNode Convert(TreeNode root) {
if(root == null)
return null;
TreeNode left = Convert(root.left);
if(left == null) {
root.left = null;
} else {
while(left.right != null) {
left = left.right;
}
root.left = left;
left.right = root;
}
TreeNode right = Convert(root.right);
root.right = right;
if(right != null)
right.left = root;
while(root.left != null) {
root = root.left;
}
return root;
}
}