In computer science, tree traversal (also known as tree search) is a form of graph traversal and refers to the process of visiting (checking and/or updating) each node in a tree data structure, exactly once.Here we are talking about Pre-order tree traversal, and we will also learn a problem of hackerrank related to it.

Is This a Binary Search Tree? Hackerrank For the purposes of this challenge, we define a binary search tree to be a binary tree with the following ordering requirements: The data value of every node in a node’s left subtree is less than the data value of that node. The data value of every node in a node’s right subtree is greater than the data value of that node. Given the root node of a binary tree, can you determine …

Balanced Brackets Hackerrank A bracket is considered to be any one of the following characters: (, ), {, }, [, or ]. Two brackets are considered to be a matched pair if the an opening bracket (i.e., (, [, or {) occurs to the left of a closing bracket (i.e., ), ], or }) of the exact same type. There are …

Binary Search Tree : Lowest Common Ancestor Hackerrank You are given pointer to the root of the binary search tree and two values v1 and v2. You need to return the lowest common ancestor (LCA) of v1 and 2 in the binary search tree. You only need to complete the function. Input Format You are given a function, node * LCA (node * root ,int v1,int v2) { } It is guaranteed that v1 and v2 are present in the …

Tree: Huffman Decoding Hackerrank Huffman coding assigns variable length codewords to fixed length input characters based on their frequencies. More frequent characters are assigned shorter codewords and less frequent characters are assigned longer codewords. A Huffman tree is made for the input string and characters are decoded based on their position in the tree. We add a ‘0’ to the codeword when we move left in the binary tree and a ‘1’ when we move right in the binary tree. …

Binary Search Tree : Insertion Hackerrank You are given a pointer to the root of a binary search tree and a value to be inserted into the tree. Insert this value into its appropriate position in the binary search tree and return the root of the updated binary tree. You just have to complete the function. Input Format You are given a function, node * insert (node * root ,int value) { } node is defined as : struct node …

Tree: Level Order Traversal Hackerrank You are given a pointer to the root of a binary tree. You need to print the level order traversal of this tree. In level order traversal, we visit the nodes level by level from left to right. You only have to complete the function. For example: 3 / \ 5 2 / \ / 1 4 6 For the above tree, the level order traversal is 3 -> 5 -> 2 -> 1 -> …