# Category Archives: Tree

## Array Representation Of Binary Heap

A Binary Heap is a Complete Binary Tree. A binary heap is typically represented as array. The representation is done as: The root element will be at Arr[0]. Below table shows indexes of other nodes for the ith node, i.e., Arr[i]: Arr[i/2] Returns the parent node Arr[(2*i)+1] Returns the left child node Arr[(2*i)+2] Returns the… Read More »

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## Enumeration of Binary Trees

A Binary Tree is labeled if every node is assigned a label and a Binary Tree is unlabeled if nodes are not assigned any label. Below two are considered same unlabeled trees o o / \ / \ o o o o Below two are considered different labeled trees A C / \ / \… Read More »

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## How to implement decrease key or change key in Binary Search Tree?

Given a Binary Search Tree, write a function that takes following three as arguments: 1) Root of tree 2) Old key value 3) New Key Value The function should change old key value to new key value. The function may assume that old key value always exists in Binary Search Tree. Example: Input: Root of… Read More »

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## Change a Binary Tree so that every node stores sum of all nodes in left subtree

Given a Binary Tree, change the value in each node to sum of all the values in the nodes in the left subtree including its own.

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## Second largest element in BST

Given a Binary Search Tree(BST), find the second largest element. Examples: Input: Root of below BST 10 / 5 Output: 5 Input: Root of below BST 10 / \ 5 20 \ 30 Output: 20 Source: Microsoft Interview We strongly recommend you to minimize your browser and try this yourself first. The idea is similar… Read More »

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## AVL with duplicate keys

Please refer below post before reading about AVL tree handling of duplicates. How to handle duplicates in Binary Search Tree?

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