Lstmxx的空间

897. 递增顺序搜索树

给你一棵二叉搜索树，请你 按中序遍历 将其重新排列为一棵递增顺序搜索树，使树中最左边的节点成为树的根节点，并且每个节点没有左子节点，只有一个右子节点。

链接

/**
 * Definition for a binary tree node.
 * class TreeNode {
 *     val: number
 *     left: TreeNode | null
 *     right: TreeNode | null
 *     constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
 *         this.val = (val===undefined ? 0 : val)
 *         this.left = (left===undefined ? null : left)
 *         this.right = (right===undefined ? null : right)
 *     }
 * }
 */

function increasingBST(root: TreeNode | null): TreeNode | null {
  if (root === null) return null
  const head = new TreeNode(0)
  let n = head
  function travese(node: TreeNode | null) {
    if (node === null) return
    travese(node.left)
    n.right = new TreeNode(node.val)
    n = n.right
    travese(node.right)
  }
  travese(root)
  return head.right
};