golang 解法, 执行用时: 0 ms, 内存消耗: 2.2 MB, 提交时间: 2021-06-10 13:11:47

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func increasingBST(root *TreeNode) *TreeNode {
	dummyNode := &TreeNode{}
	resNode := dummyNode

	var inorder func(*TreeNode)
	inorder = func(node *TreeNode) {
		if node == nil {
			return
		}
		inorder(node.Left)

		// 在中序遍历的过程中修改节点指向
		resNode.Right = node
		node.Left = nil
		resNode = node

		inorder(node.Right)
	}
	inorder(root)

	return dummyNode.Right

}

golang 解法, 执行用时: 0 ms, 内存消耗: 2.2 MB, 提交时间: 2021-06-10 11:38:14

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func increasingBST(root *TreeNode) *TreeNode {
    var ans []int
    
    var inorder func(*TreeNode)
    inorder = func(node *TreeNode) {
        if node != nil {
            inorder(node.Left)
            ans = append(ans, node.Val)
            inorder(node.Right)
        }
    }
    inorder(root)

    r := &TreeNode{}
    curNode := r

    for _, val := range ans {
        curNode.Right = &TreeNode{Val: val}
        curNode = curNode.Right
    }
    return r.Right

}