JavaScript SDE Cheat Sheet

I am currently running #250DaysOfJSQuestions on twitter where I share one JavaScript interview questions daily, follow me on twitter @learnersbucket for web dev and interview related content.

In 2019 January, during the lockdown, I had started solving problems in JavaScript and writing articles on it on my blog, over the time I have solved 300+ problems. This cheat sheet contains list of problem that can be asked to a JavaScript dev.

This is a curated list of solved problems in JavaScript categorized on the type & nature of the problem which you can refer to and use as a cheat sheet for interview preparation.

It contains Data Structures & Algorithms, functions, async, closure, & hoisting-related problems.

DataStructures

• Javascript array: Complete reference.
• Javascript Objects: Complete Reference.
• Javascript String: Complete Reference.
• Implement Stack data structure in javascript.
• Queue data structure in javascript.
• List data structure in javascript.
• Linked list data structure in javascript.
• Implement stack using linked list.
• Implement queue using linked list.
• Doubly linked list implementation in javascript.
• Implement deque data structure in javascript.
• Deque data structure with doubly linked list.
• Circular linked list implementation in javascript.
• Circular Doubly linked list in javascript.
• Priority Queue Implementation in javascript.
• Tree data structure in javascript.
• Heap data structure in Javascript.
• Treap data structure in Javascript.
• Trie data structure in Javascript.
• Javascript graph data structure.
• AVL Tree in Javascript.

Algorithms

It contains only the important ones, you can checkout the whole list here.

• Implement Stack data structure in javascript.
• Print all subarrays with a given sum k in an array.
• Program to check if a subarray with 0 sum exits or not.
• Find distinct ways to climb the stairs in javascript.
• Caesar Cipher in javascript.
• Count all substrings having character k.
• Number of subarrays with given sum k.
• Implement a Stack using Queue.
• Implement queue using two stack.
• Learn how to implement two stack with an array.
• Alternatively merge two different arrays.
• Implement stack with max and min function.
• Merge two sorted linked list.
• How to find loop in linked list.
• Find height and width of binary tree.
• Tree traversal in Javascript.
• Flood fill algorithm in javascript.
• Find longest palindrome in a string.
• Find all anagrams substring in a string.
• Find the largest sum of contiguous subarray.
• Check if binary tree has path sum.
• Rotate matrix 90 degrees clockwise and anti-clockwise.
• Find the intersection point of two linked list.
• Trapping rain water in javascript.
• Diagonal traversal of binary tree.
• Check if binary tree is symmetric.
• Find floor and ceil of binary search tree.
• Find Least Common Ancestor (LCA) of binary tree.
• Find kth smallest and largest element in BST.
• Serialize and Deserialize Binary Tree.
• Find inorder successor of a given key in a BST.
• Find inorder predecessor of a given key in a BST.
• N meetings in one room.
• knapsack problem in Javascript (Bounded & Unbounded).
• LRU cache in Javascript.
• Fractional knapsack problem.
• Longest Common Subsequence.
• Longest repeated subsequence.
• Longest Consecutive Sequence.
• Deepest leaves sum of binary tree.

Sorting

• Selection sort in javascript.
• Dutch national flag problem.
• Bubble sort algorithm in javascript.
• Recursive Bubble sort algorithm.
• Insertion sort algorithm in javascript.
• Recursive Insertion Sort Algorithm.
• Sorting a linked list.
• Bubble sort using two stacks.
• Merge sort in javascript.
• Iterative merge sort algorithm.
• Merge sort a linked list.
• Quick sort algorithm in Javascript.
• Quick sort Iterative.
• Quick sort using linked list.
• Heap sort algorithm in Javascript.
• Iterative heap sort in Javascript.
• Counting Sort Algorithm In Javascript.
• Radix sort algorithm in Javascript.
• Bucket Sort Algorithm.
• Shell Sort Algorithm In Javascript.

Searching

• Linear search algorithm in javascript.
• Binary search in javascript.
• Binary search in javascript.
• Search in a sorted rotated array.

JavaScript specific problems.

I am currently working on this list, these are few random questions, you can find the full list here.

• How to merge objects in javascript.
• Compare two array or object with JavaScript.
• What is debouncing in javascript?.
• What is throttling in javascript?.
• Number increment counter in Javascript (React).
• Detect idle state (inactive) in Javascript.
• Deep flatten object in Javascript – 1.
• Currying in JavaScript.
• Capture product visible on viewport when user stops scrolling.
• Animate elements in a sequence.
• Create Pausable auto incrementer.
• Implement clearAllTimeout in JavaScript.
• Implement ClearAllInterval in JavaScript.
• Singleton design pattern in JavaScript.
• Observer design pattern in JavaScript.
• Remove cycle from the object in JavaScript.
• Execute async functions in Series.
• Retry promises N number of times in JavaScript.
• In-memory filesystem library in JavaScript.

JavaScript projects.

• Create simple calculator with javascript.
• Whack a mole game in javascript.
• Rock, Paper, Scissor, Lizard, Spock game in javascript.
• Eye follow cursor in javascript.
• Text typing effect in javascript.
• Word falling effect in javascript.
• Day night toggle switch in javascript.
• Day night toggle switch in javascript.
• Roman to numeral converter javascript.
• Tic tac toe game in javascript with bot.

More questions will be added to it as and when I write them.