nikoo28

Question: Given the root pointer to a binary tree, find the left view of the tree. Input: Sample Tree (Pointer to node 1 is given). Output: 1, 2, 4 At a single glance of the problem, we can understand that we need to perform a level order traversal on the tree. This is similar to finding the number of levels in a tree. At the start of each level, we just print the first element. This can be done with the algorithm below:- Time Complexity:- O(n) Space Complexity:- O(n) Ideone …

In C, a structure cannot have static members, but in C++ a structure can have static members. For example, following program causes compilation error in C, but works in C++. Feel free to add your opinion.

Symbol Tables can be implemented in many ways and here are some of them. Unordered Array Implementation With this method, just maintaining an array is enough. It needs O(n) time for searching, insertion and deletion in the worst case. Ordered [Sorted] Array Implementation In this we maintain a sorted array of keys and values. Store in sorted order by key keys[i] = ith largest key values[i] = value associated with ith largest key Since the elements are sorted and stored in arrays, we can use simple binary search for finding …

Since childhood, we have all used a dictionary, and many of us have used a word processor (say Microsoft WORD) which comes with a spell checker. The spell checker is also a dictionary but limited. There are many real time examples for dictionaries and few of them are:- Spelling checker The data dictionary found in database management applications Symbol tables generated by loaders, assemblers, and compilers Routing tables in networking companies (DNS Lookup) In computer science, we generally use the term symbol table rather than dictionary, when referring to the …

Question: How many binary trees are possible with n nodes? Input: Nodes = 3 Output: Answer = 5 For, example consider a tree with 3 nodes (n = 3), it will have a maximum combination of 5 different trees In general, if there are n nodes, there exist (2n)!/(n+1)! different trees.

Question: Given the root pointer to a binary tree, find the LCA (Least Common Ancestor) of two nodes in the tree. Input: Sample Tree (Pointer to node 1 is given). Find LCA of node 5 and 4 Output: Answer = 3 A simple recursive approach can be used to find the LCA (Least common ancestor).

Question: Given 2 binary trees, determine if they are mirror of each other Input: 2 tree pointers are given. (Root pointer) Output: TRUE We can again apply the recursive sub-structure property of the tree here. The algorithm can be implemented as:- Time Complexity:- O(n) Space Complexity:- O(n) due to a recursive stack

Question: Given the root pointer to a binary tree, find the sum of all its elements without using recursion. Input: Sample Tree (Pointer to node 1 is given). Output: Sum = 15 We discussed how to find the sum of all elements of a binary tree using recursion in this post. Given a binary tree, find the sum of all elements. If recursion seems tough to you , you can always go by the iterative approach and use Level Order Traversal of binary tree. While performing a level order traversal, …

Question: Given the root pointer to a binary tree, find the sum of all its elements. Input: Sample Tree (Pointer to node 1 is given). Output: Sum = 15 This is a very simple problem. Since the tree follows a recursive sub-structure, we can recursively call left tree sum, right tree sum and then add their values to the current node data.

Question: Given a binary tree, find its mirror tree. Input: A tree pointer is given. (Root pointer) Output: Pointer of mirrored tree. We can easily get the mirrored tree by a simple recursive algorithm. We traverse the tree and swap the left and right pointers. Time Complexity:- O(n) Space Complexity:- O(n) (due to recursive stack)