Essential DSA Topics For Front-End Developers

The importance of Data Structures and Algorithms (DSA) can vary based on different companies. For MAANG companies we will have to be well-versed in the DSA concept. On the other hand, for the second-tier company, the level of DSA knowledge is slightly lower and for the startup company, the knowledge of DSA may be at a more basic level. Here’s a list of important DSA topics.

1. Array

• Check if an array is sorted and rotated
• Merge two sorted arrays
• Program for array left rotation by d positions
• Remove duplicates from Sorted Array
• Leaders in an array
• Stock Buy Sell to Maximize Profit
• Trapping Rain Water
• Maximum circular subarray sum
• Median of two Sorted Arrays of Different Sizes
• Length of the longest alternating even odd subarray

2. String

• Check if given strings are rotations of each other or not
• Length Of Last Word in a String
• Check if two given Strings are Isomorphic to each other
• Find maximum occurring character in a string
• Program to reverse a string
• Reverse words in a given string
• Case-specific Sorting of Strings
• Rabin-Karp Algorithm for Pattern Searching
• Find the starting indices of the substrings in string (S) which is made by concatenating all words from a list(L)
• Longest Valid Parentheses

3. Recursion

• Program to Find and Print Nth Fibonacci Numbers
• Josephus Problem
• Lucky Numbers
• Write program to calculate pow(x, n)
• Program for Tower of Hanoi Algorithm

4. Searching

• Search an element in an unsorted array using minimum number of comparisons
• Majority Element
• Find a peak element which is not smaller than its neighbours
• Find the two repeating elements in a given array
• Maximum water that can be stored between two buildings
• Search an element in a sorted and rotated Array
• Search in a sorted 2D matrix
• Maximum sum not exceeding K possible for any rectangle of a Matrix
• k-th smallest absolute difference of two elements in an array
• Split the given array into K sub-arrays such that maximum sum of all sub arrays is minimum

5. Sorting

• Sort a binary array using one traversal and no extra space
• Union and Intersection of two sorted arrays
• Maximum product of a triplet (subsequence of size 3) in array
• Find minimum difference between any two elements (pair) in given array
• Sort an array of 0s, 1s and 2s | Dutch National Flag problem
• Merge 3 Sorted Arrays
• K’th Smallest/Largest Element in Unsorted Array
• Find a triplet that sum to a given value
• Maximum adjacent difference in an array in its sorted form
• Sort elements by frequency

6. Matrix

• Print matrix in snake pattern
• Program to find transpose of a matrix
• Rotate a matrix by 90 degree in clockwise direction without using any extra space
• Print a given matrix in spiral form
• Search in a row wise and column wise sorted matrix
• Check if given Sudoku board configuration is valid or not
• A Boolean Matrix Question

7. Hashing

• Implementing own Hash Table with Open Addressing Linear Probing
• Separate Chaining Collision Handling Technique in Hashing
• Quadratic Probing in Hashing
• Happy Number
• Find winner of an election where votes are represented as candidate names
• Distribute N candies among K people
• Check whether the string can be printed using same row of qwerty keypad
• Longest Consecutive Subsequence

8. Linked List

• Reverse a Linked List
• Remove duplicates from a sorted linked list
• Sort a linked list of 0s, 1s and 2s
• Remove duplicates from an unsorted linked list
• Add two numbers represented by Linked List
• Rotate a Linked List
• LRU Cache Implementation
• Merge K sorted linked lists
• Partitioning a linked list around a given value and keeping the original order
• Pairwise Swap Nodes of a given Linked List

9. Stack

• Delete middle element of a stack
• Reduce string by removing outermost parentheses from each primitive substring
• Implement two Stacks in an Array
• The Stock Span Problem
• Design a stack that supports getMin() in O(1) time and O(1) extra space
• Next Greater Element (NGE) for every element in given Array
• The Celebrity Problem
• Largest Rectangular Area in a Histogram using Stack

10. Queue

• Array implementation of queue
• Queue using Stacks
• Find the arrangement of queue at given time
• Queue – Linked List Implementation
• An Interesting Method to Generate Binary Numbers from 1 to n
• Implement Stack using Queues
• Reversing the first K elements of a Queue

11. Tree

• Postorder Traversal of Binary Tree
• Find the Maximum Depth or Height of given Binary Tree
• Level Order Traversal (Breadth First Search or BFS) of Binary Tree
• Print level order traversal line by line
• Print Left View of a Binary Tree
• Check for Children Sum Property in a Binary Tree
• Convert a Binary Tree into its Mirror Tree
• Vertical width of Binary tree
• Print all nodes at distance k from a given node
• Construct a Binary Tree from Postorder and Inorder
• Flatten a binary tree into linked list
• Maximum Path Sum in a Binary Tree

12. Binary Search Tree

• Searching in Binary Search Tree
• A program to check if a Binary Tree is BST or not
• Print Common Nodes in Two Binary Search Trees
• Construct BST from its given level order traversal
• Lowest Common Ancestor in a Binary Search Tree
• Deletion in Binary Search Tree (BST)
• Find the closest element in Binary Search Tree
• Merge two BSTs with limited extra space
• Two nodes of a BST are swapped, correct the BST

13. Heap

• K-th Greatest Element in a Max-Heap
• Sort a nearly sorted (or K sorted) array
• Find K most occurring elements in the given Array
• K’th largest element in a stream

14. Graph

• Distance of nearest cell having 1 in a binary matrix
• Minimum time required to rot all oranges
• Find the number of islands using DFS
• Level of Each node in a Tree from source node (using BFS)
• Find the number of islands using DFS
• Detect cycle in an undirected graph
• Detect Cycle in a Directed Graph
• Check if removing a given edge disconnects a graph
• Clone an Undirected Graph
• Clone a Directed Acyclic Graph

15. Backtracking

• Combinational Sum
• Iterative Letter Combinations of a Phone Number
• N Queen Problem
• N Queen Problem using Branch And Bound
• Rat in a Maze with multiple steps or jump allowed
• Find Maximum number possible by doing at-most K swaps

16. Dynamic Programming

• Count all possible paths from top left to bottom right of a mXn matrix
• Sum of all substrings of a string representing a number
• Count ways to reach the n’th stair
• Minimum number of jumps to reach end
• Longest Increasing Subsequence (LIS)
• Maximize the number of segments of length p, q and r
• 0/1 Knapsack Problem
• Egg Dropping Puzzle

Front-end developer creates the user-facing component such as the user interface(UI) and user experience(UX), that determines how the user interacts with the digital product. Front-end engineer works with generally HTML, CSS, JavaScript, and frameworks like React or Angular. But having a solid foundation in DSA, we can optimize the performance of the website and deliver a great user experience.

In this article, we will explore the importance of DSA, why is it necessary, and How much DSA is required for the front end.