Most of us know what recursion is and can write recursive code if we are asked to. But when we try to solve advance problems(i.e binary tree, binary search tree etc.) and see recursive solutions, we get confused about how that code is working, so in this post, I will…

The problem asks you to build a caching(cache is something that stores computation for lookups or it may also store redundant data for quick access to speed up future requests) system that has all the usual cashing features(i.e insert, delete, search) but it has the ability to get rid of…

The basic workflow of c++ code is: source file-> compiler -> executable binary file. But how do we get to the executable binary file from source code? Let's see a c++ code first: What is in the Source file? The first thing we see in the above code is…

The problem asks you to find a number from a sorted array but all the numbers has been shifted by some amount either left or right.For Example:{9, 19, 21, 2, 8} the array is sorted from index 0 to 2 and then we have the value 2 which is less…

In this post I’m not doing in depth discussion on how these standard libraries works behind the scene. I will just show what they do and how to use them. Sort sort: It orders the elements from beginning to end in O(nlogn) complexity. By default it the elements in ascending order…

A subsequence is a group of characters that appears sequentially but it doesn’t have to be contiguous though it can be. For example s = “AFPKL” in this string valid sub-sequences can be “AFP”, “APK”, “AFKL” etc. So, the problem is asking us to return the sequence of the…

Binary search tree(BST) is a kind of binary tree(tree where each node has at most 2 child nodes) where any node of the tree will be less than all its right children and greater than all its left children. For Instance To implement BST will implement three things that we…

Edit distance problems is: if we are given two string word1 and word2 what is the minimum number of operation needed to transform a into b. The operations are: substitution, insertion and deletion. You can find this problem in interviewbit and leetcode. In order to solve this problem, we have…

What is Breadth First Search(BFS)? BFS is a graph traversal method that traverses the graph iterative way level by level. That means it traverses the graph “breadth first”, starting from the source then the neighbor of the source then the next level and so on. For example: If we traverse…