Leetcode - Increasing Order Search Tree
https://leetcode.com/problems/increasing-order-search-tree/
Given a binary search tree, rearrange the tree in in-order so that the leftmost node in the tree is now the root of the tree, and every node has no left child and only 1 right child.
Example 1: Input: [5,3,6,2,4,null,8,1,null,null,null,7,9] 5 / \ 3 6 / \ \ 2 4 8 / / \ 1 7 9 Output: [1,null,2,null,3,null,4,null,5,null,6,null,7,null,8,null,9] 1 \ 2 \ 3 \ 4 \ 5 \ 6 \ 7 \ 8 \ 9
func increasingBST(root *TreeNode) *TreeNode { result := []int{} stack := []*TreeNode{} node := root for node != nil || len(stack) != 0 { for node != nil { stack = append(stack, node) node = node.Left } if len(stack) != 0 { node = stack[len(stack)-1] result = append(result, node.Val) stack = stack[:len(stack)-1] node = node.Right } } //fmt.Println("result: ", result) root = &TreeNode{} node = root for i := 0; i < len(result); i++ { node.Right = &TreeNode{ Val: result[i], } node = node.Right } return root.Right }