Here is a simple python for loop: Notice that append() function is called to add elements to the list. Let’s write the same using List comprehension: The simplest way to understand why list comprehensions are faster is by noticing that in the first example, append() function is called explicitly. But in list comprehension, it is …
Read More List comprehensionsThe following visuals will give you an idea about how the spiral or zigzag order traversal looks like. This traversal is based on Level order traversal. We need to keep track of the nodes in each level to display accordingly. As we can see above, tracking each level is very important during this traversal. Approach …
Read More Spiral or Zigzag Traversal in a Binary TreeRight View – All the nodes visible when viewed from the right side of a tree. Left View – All the nodes visible when viewed from the left side of a tree. Consider a simple example below. Notice the views. Consider another example below where the root node A does not have left subtree. Notice …
Read More Left and Right Views in a Binary TreeFinding the Kth biggest using Heap Sort Sort it by getting the biggest, then the next biggest, then the next and so on. . . Every time to get the next biggest – get the biggest and fix the heap takes —-> logn Hence, for kth biggest –> klogn 2nd biggest—>2logn 3rd biggest —>3logn Middle …
Read More Find the kth largest number or Median of mediansThe idea is to always keep a reference to the previous-node and next-node. We will always be operating in the context of the current node. In every iteration, the steps will be:1. Get reference to next node.2. Detach the link between current and next node.3. Create a link between current and previous node.4. Update Previous …
Read More Reverse a Singly Linked ListProperty: A binary tree is a Binary Search Tree when all elements to the left is lesser than the current node and the ones to the right are greater than that node. Simplest way to understand is when you print a left node, root and right node, you should get a sorted list based on property …
Read More Find whether Binary tree is a Binary Search TreeWe must always follow the below 2 points when deleting a node from Binary Search Tree: Delete the node. Retain the Binary Search Tree property. Consider the following scenarios that we encounter when deleting a node from a BST: Scenario 1: Deleting a leaf node or a childless node. This is certainly the easiest case …
Read More How to delete a node from Binary Search Tree