The value of root node will be i if -1 is present at index i in the array. Algorithms is as follows: Sort the array of integers. In this article, we are going to see how we can create a height-balanced binary Search tree from a given sorted 1-D array? This takes O(nlog(n)) time Construct a BST from sorted array in O(n) time Given an array A which represents a binary tree such that the parent-child relationship is defined by (A[i], i) for every index i in A, build binary tree out of it. Construct Binary Tree from Parent Array Medium Accuracy: 45.96% Submissions: 18524 Points: 4 Given an array of size N that represents a Tree in such a way that array indexes are values in tree nodes and array values give the parent node of that particular index (or node). The problem “Construct Binary Tree from given Parent Array representation” states that you are given an array. That is, elements from left in the array will be filled in the tree level wise starting from level 0. It may be assumed that the input provided to the program is valid. Given an array of elements, our task is to construct a complete binary tree from this array in level order fashion. Pay attention to the word " height-balanced " as it plays a huge role. Yes, there is easy way to construct a balanced Binary Search Tree from array of integers in O(nlogn). My thought process on this is that this algorithm is incorrect. This input array represents a binary tree. We know that any comparison-based sorting algorithm has a Now you need to construct a binary tree on the basis of this input We can create a binary search tree with the list by just creating a skew tree from the array elements, where we will just put the list nodes as a right child only. To create a binary tree from an unsorted array of size n of integers, one would need to first sort the array. Given an array in Pre-Order(root, left, right) traversal order, I need to construct a binary tree, not a binary search tree, just a binary tree where each root can have 0, 1 or 2 children. Construct a Binary Search Tree (BST) for the following sequence of numbers-50, 70, 60, 20, 90, 10, 40, 100 When elements are given in a sequence, Always consider the first element as the root node.