Data structures

Problems.md

Topics to study

• DS

  • BFS
  • Hash to count unique
  • Linked List
  • Tree
  • Sorting Algorithms

• Design

  • stystem design
  • design patterns -> strategy pattern
  • Solid principles
  • architecture patterns
  • ACID

• Problem Solving

• Coding Questions

  • JS, react, regex
  • new in JS/ES6 and other version
  • MongoDb, SQL vs No SQL
  • Rest API Methods

• Architecture

  • React redux architecture
  • routes

• Question Bank -> This too

• Interview Cake: Basics of DS -> check glossary menu

  • DS
  • heap

• dlucidone

common stuff

• ES way Object.entries(myObj)
• plain js get index of clicked node
• XHR Request

Array Problems

• Find single missing number in array
• Find multiple missing number in array
• FInd duplicates in array
• remove duplicates in place
• find 2nd highest number in the array -> same can be used for smallest number and combined
• Find All Pairs That Sum to a Target Value : Greedy Approach
• reverse an array in place
• merge sorted arrays
• Dutch flag problem
• sort logs with timestamps from n different files (merge n sorted arrays)

Linked list

• Find middle of linked list
• check if a given linked list contains a cycle
• find the start of the cycle the intersection always comes at the center of loop... once found set the slow pointer to head and inc both slow anf fast by 1 node
• Reverse a linked list
• Remove duplicate nodes from unsorted linked list
• find length with recursion -> new sol
• [find the third node from the end in a singly linked list]
• [Add two numbers represented by linked lists]
• Find intersection of two Linked list
• palindrome in heterogeneous linked list

Strings

• Angrams - use charCodeAt.. take sum of all letters (in same loop) and equate
• 1Reverse string recursively
• 2Reverse a string with recursion
• find all permutations of a string
• Is palindrome?

Binary tree

• height of binary tree
• [detect if binary tree is bst]
• [add all leaf nodes of binary tree to linked list]
• Traversal types - preorder, in,post => another sol
• breadth first search in binary tree used to find shortest path between nodes... shortest route

https://www.i-programmer.info/programming/javascript/1899-javascript-data-structures-the-binary-tree.html

System design and Architecture

• Cheetsheet

most asked topics

• Hash tables
• Linked lists
• Breadth-first search, depth-first search
• Quicksort, merge sort
• Binary search
• 2D arrays
• Dynamic arrays
• Binary search trees
• Dynamic programming
• Big-O analysis
• --- sytem design
• HTTP (at the protocol level)
• Databases (indexes, query planning)
• CDNs
• Caching (LRU cache, memcached, redis)
• Load balancers
• Distributed worker systems
• High scalibility ()must read
• SOLID princilpes
• ACID

Design problems

• design chess game
• Elevator design
• Hit problem
• design efficient DS for the given operations
• Stream Processing
• realtime streaming huge logs
• slot machine generate random number
• Design-video-sharing-platform-like-Youtube

Architecture

• Redux
• Thunk

Questions

• management
• Reverse interview
• Negotiating salary
• Tech interview handbook