Introduction to Data Structures

Big O Space Complexity

Asymptotic Analysis and Big O

Introduction to Big O, Time Complexity

What you're going to get from this course

Big O Logarithm

Welcome! How to make best use of this course (Please Watch)

Arrays Data Structures Crash Course

CODING INTERVIEW Q1 (Easy) Sorted Squared Array

Method 1, Big O Analysis

JS Code - Method 1

JavaScript Code - Method 2

Method 2

CODING INTERVIEW Q2 (Easy) Monotonic Array

Method and Big O analysis

JavaScript Code - Monotonic Array

Celebrating Milestones

Recursion Basics

Recursive Leap of Faith

Recursion vs Iteration

Ways to write Base condition

Visualising Recursion

Recurrence relation

How to Solve Recursion Questions

Recursion is everywhere

Complexity Analysis of Recursive Solutions

Recursion Approaches - 0 to N and N to 0

CODING INTERVIEW QUESTION (Medium) k-th symbol in Grammar

Approach(k-th symbol in Grammar)

Pseudocode (k-th symbol in Grammar)

Complexity Analysis(k-th symbol in Grammar)

JavaScript Solution (k-th symbol in Grammar)

Pseudocode

Complexity Analysis

Approach 1

JavaScript Solution 1 Josephus problem Method 1

CODING INTERVIEW QUESTION (Medium) Josephus problem

Approach 2

Pseudocode

JavaScript Solution 2 Josephus problem Method 2

Complexity Analysis

Approach 3

Complexity Analysis

JavaScript Solution 3 Josephus problem Method 3

Celebrating Milestones

Identifying that wew can use Recursion

CODING INTERVIEW QUESTION (Medium) Tower of Hanoi

Approach

Recursion Tree

JavaScript Solution Tower of Hanoi

CODING INTERVIEW QUESTION(Medium) Power Sum

JavaScript Solution Power Sum

Method and Big O Analysis

Celebrating Milestones

Complexity Analysis Tower of Hanoi

What is Backtracking

How is it different from Recursion

How does Backtracking work

Pass by reference change inplace

Identify when to use Backtracking

Blueprint to solve questions using Backtracking

CODING INTERVIEW QUESTION (Medium) Permutations

Approach

Pseudocode

CODING INTERVIEW QUESTION(Medium) Permutations 2

Complexity Analysis

Approach

Pseudocode

JavaScript Code Permutations 2

Complexity Analysis Permutations 2

Celebrating Milestones

CODING INTERVIEW QUESTION(Medium) Subsets

Subsets - Comparison with Backtracking Blueprint

Method

Subsets - Complexity Analysis

CODING INTERVIEW QUESTION(Medium) Subsets 2

JavaScript Code - Subsets

code walkthrough (optional)

Subsets 2 Complexity Analysis

JavaScript Code Subsets 2

Celebrating Milestones

CODING INTERVIEW QUESTION(Medium) Combinations

Approach

Combinations Complexity Analysis

JavaScript Code Combinations

JavaScript Code Combinations with Optimisation

Combinations Optimisation

CODING INTERVIEW QUESTION ( Medium) Combinations Sum 1

Sidenote Max number of nodes

Complexity Analysis part 1

Complexity Analysis part 2

Celebrating Milestones

JavaScript Code Combinations Sum 1

CODING INTERVIEW QUESTION (Medium) Combinations Sum 2

Complexity Analysis

JavaScript Code Combination Sum 2

Celebrating Milestones

CODING INTERVIEW QUESTION(Hard) Sudoku Solver

isValid check for Sudoku Solver

Pseudocode

CODING INTERVIEW QUESTION(Hard) N Queen

Complexity Analysis

JavaScript Code Sudoku Solver

Approach

Pseudocode

Complexity Analysis

JavaScript Code N Queen

Dynamic Programming - Patterns

Introduction to Dynamic Programming (DP)

Why writing the Recursive solution helps to write the Bottom up approach

Identifying Dynamic Programming Questions

Approach to solve DP(Dynamic Programming) Questions

CODING INTERVIEW QUESTION(Easy) Fibonacci

Approaches

Approach 1 Recursion

JavaScript Code - Recursion

Complexity Analysis Approach 1 - Recursion

Approach 2 Memoization

Complexity Analysis Approach 2 - Memoization

JavaScript Code Approach 2 - Memoization

Approach 3 Tabulation

Complexity Analysis Approach 3 - Tabulation

JavaScript Code Approach 3 - Tabulation

Approach 4 Space Optimised Tabulation + Complexity Analysis

CODING INTERVIEW QUESTION(Easy) Climbing Stairs

JavaScript Code Approach 4 -Space Optimised Tabulation + Complexity Analysis

Approach

CODING INTERVIEW QUESTION(Easy) Min Cost Climbing Stairs

Recursive Approach

JavaScript Code Recursive Approach

Memoization Approach

JavaScript Code Memoization Approach

Tabulation Approach

JavaScript Code Tabulation Approach

Complexity Analysis

CODING INTERVIEW QUESTION(Medium) 01 Knapsack

Recursive Approach Pseudocode

Recursive Approach Complexity Analysis

Approach 1 Recursion

JavaScript Code Recursive Approach

Memoization Pseudocode

JavaScript Code Memoization

Approach 2 Memoization

Memoization Complexity Analysis

JavaScript Code Tabulation

JavaScript Code Space Optimised Tabulation

Tabulation Complexity Analysis

Approach 4 Space Optimised Tabulation Approach

Space Optimised Tabulation Approach Complexity Analysis

Approach 3 Tabulation

CODING INTERVIEW QUESTION(Medium) Unbounded Knapsack

Complexity Analysis

Tabulation Approach

JavaScript Code Unbounded Knapsack

CODING INTERVIEW QUESTION(Medium) LCS

JavaScript Code LCS

Recursion Tree and Complexity Analysis

Tabulation Complexity Analysis

JavaScript Code Tabulation - LCS

JavaScript Code Memoization - LCS

Approach 4 Space Optimised Tabulation - LCS

JavaScript Code Space Optimised Tabulation - LCS

Approach 3 Tabulation

Identifying this as an LCS Type Question

CODING INTERVIEW QUESTION(Medium) Edit Distance

Pseudocode

Recursion Complexity Analysis

Approach 1 Recursion

JavaScript Code Recursive Approach(Edit Distance)

Approach 2 Memoization

Tabulation Complexity Analysis

JavaScript Code Memoization(Edit Distance)

JavaScript Code Tabulation (Edit Distance)

Approach 4 Space Optimised Tabulation

Approach 3 Tabulation

JavaScript Code Space Optimised Tabulation ( Edit Distance)

CODING INTERVIEW QUESTION(Medium) Longest Increasing Subsequence (LIS)

Approach 1 Recursion - LIS

Complexity Analysis - Recursion - LIS

JavaScript Code - Recursion - LIS

Complexity Analysis - Memoization

Recursion Tree

JavaScript Code - Memoization - LIS

Complexity Analysis - Tabulation - using a 2D dp array

Approach 3 Tabulation - using a 2D dp array

Dry run

JavaScript Code - Tabulation using a 2D dp array - LIS

Approach 4 Tabulation - using a 1D dp array

Complexity Analysis- Tabulation - using a 1D dp array

Dry run

Approach 5 using Binary Search - LIS

JavaScript Code-Tabulation - using a 1D dp array

Part 1 - Approach 5 using Binary Search - LIS

Part 2 - Approach 5 using Binary Search - LIS

Binary Search for this question ( refer Binary Search section for more details)

Complexity Analysis - Approach 5 using Binary Search - LIS

Why Sort

CODING INTERVIEW QUESTION(Medium) Max Length of Pair Chain

JavaScript Code - Approach 5 using Binary Search - LIS

Approach

JavaScript Code - Max Length of Pair Chain

Approach

Complexity Analysis

CODING INTERVIEW QUESTION(Hard) Russian Doll Envelopes

JavaScript Code

Introduction to Gap Strategy or Length wise Iteration

CODING INTERVIEW QUESTION(Medium) Palindromic Substrings

Approach Recursion with memoization

Intuition for Approach

Idetifying this as a DP question

pseudocode

Filling the Memoization table

iterate length wise

Recursion with memoization Complexity analysis

Tabulation approach Complexity Analysis

JavaScript Code Recursion with memoization

Tabulation approach

JavaScript Code Tabulation

Approach (Tabulation)

CODING INTERVIEW QUESTION(Medium) Longest Palindromic Substring

Complexity Analysis

JavaScript Code

CODING INTERVIEW QUESTION(Medium) Longest Palindromic Subsequence

Complexity Analysis

JavaScript Code

Approach

Introduction to the Partition method

CODING INTERVIEW QUESTION(Medium) Palindrome Partitioning

Side note Computing n C r

Pseudocode

CODING INTERVIEW QUESTION(Hard)Palindrome Partitioning 2 ( Minimum Cuts) - Hard

JavaScript Code Palindrome Partitioning

Approach 1 Recursion

JavaScript Code Memoization - Palindrome Partitioning 2

JavaScript Code Recursion - Palindrome Partitioning 2

Tabulation - Approach A Palindrome Partitioning 2

JavaScript Code Tabulation - Approach A Palindrome Partitioning 2

Complexity Analysis

Dry Run

Dry run

Tabulation - Approach B Palindrome Partitioning 2

Pseudocode

JavaScript Code Tabulation - Approach A Palindrome Partitioning 2

CODING INTERVIEW QUESTION(Medium) Word Break

Approaches

Approach 1 Tabulation

Complexity Analysis

JavaScript Code

APPROACH 2 Part A Memoization

JavaScript Code - Recursion

JavaScript Code- Memoization

Pseudocode

APPROACH 2 Part B Tabulation

Complexity Analysis

CODING INTERVIEW QUESTION(Hard) Matrix Chain Multiplication

Pseudocode

JavaScript Code

How to do Matrix Multiplication

Back to the Question

Intuition

Pseudocode

Approach

JavaScript Code - Greedy Approach

CODING INTERVIEW QUESTION Task Scheduler

JavaScript Code

Coding Interview Q1(Medium) Rotate Array

Method and Big O analysis

JavaScript Code Solution

Coding Interview Q2(Medium) Container with most water

JavaScript Code Method 1

Code walkthrough and Big O analysis

Method 1 and Big O analysis

JavaScript Code Method 2

Method 2 and Big O analysis

Code walkthrough

Coding Interview Q1(Easy) Two Sum

Method 1, Big O analysis

Hash Table Data Structures Crash Course

Code Walkthrough

JavaScript Code

Method 2, Big O analysis

Coding Interview Q2(Easy) Isomorphic Strings

Code Walkthrough

Method and Big O analysis

JavaScript Code

Introduction to 2 Pointer Pattern

CODING INTERVIEW QUESTION Best Time to Buy and Sell Stock

Code

CODING INTERVIEW QUESTION Two Sum 2

Complexity Analysis

Method

Code

CODING INTERVIEW QUESTION 3 Sum

Complexity Analysis

Method 1

Code - Method 1

Method 2

Code

Introduction to Sliding Window Pattern

CODING INTERVIEW QUESTION Max Avg Subarray I

JS Code

CODING INTERVIEW QUESTION Repeated DNA Sequence

Test cases

Method 1

JS Code Method 1

(Optional) Basics - Converting a number from base 4 to base 10

Method 2

JS Code Method 2

CODING INTERVIEW QUESTION Sliding Window Maximum

Test Cases

SideNote Deque data structure

Method - Part 1 ( Intuition Observations)

Method - Part 2 (Walkthrough)

CODING INTERVIEW QUESTION Minimum Window Substring

JS Code

Test Cases

CODING INTERVIEW QUESTION Min Size Subarray Sum

Method

Walkthrough

JS Code

Method

CODING INTERVIEW QUESTION Frequency of most frequent element

JS Code

JS Code

Method - Part 2 ( Walkthrough)

Method - Part 1

Data Structures Crash Course Strings

Coding Interview Q1(Easy) First Non Repeating Character

JavaScript code

Method 1 and Big O analysis

Code walkthrough

Method 2 and Big O analysis

JavaScript code

Code walkthrough

Coding Interview Q2(Easy) Is Palindrome

JavaScript code

Method 1 and Big O analysis

Code walkthrough

Method 2 and Big O analysis

JavaScript code

Code walkthrough

Method 3 and Big O analysis

JavaScript code

Code walkthrough

Coding Interview Q1(Medium) Longest Sub string with Unique characters

Coding Interview Q2(Medium) Group Anagrams

JavaScript code

Code walkthrough

method and Big O analysis

JavaScript code

Coding Interview Q1 (Easy) Binary Search Algorithm

JavaScript Code Iterative

Coding Interview Q2(Medium) Search in rotated sorted array

JavaScript Code Recursive

JavaScript Code

Method and Big O analysis

Coding Interview Q1(Medium) Search for range

Coding Interview Q2(Medium) Search in Matrix

JavaScript Code - Iterative

JavaScript Code - Recursive

Coding Interview Q1 Bubble Sort Algorithm

JavaScript Code

Code Walkthrough

Coding Interview Q2 Insertion Sort Algorithm, Big O analysis

Insertion sort is a stable sorting Algorithm

Python code

Coding Interview Q1 Selection Sort Algorithm, Big O analysis

Coding Interview Q2 Merge Sort Algorithm

JavaScript Code

JS Code Walkthrough

Method and Big O analysis

Coding Interview Q1 Quick Sort Algorithm

Optimise Time Complexity

JS Code walkthrough

Optimise Space Complexity

Call stack walkthrough

Coding Interview Q2 Radix Sort Algorithm, Big O analysis

JavaScript Code

CODING INTERVIEW QUESTION Merge Intervals

Introduction to Merge Intervals Coding Interview Question Pattern

Complexity Analysis

Method - Part 2 (Walkthrough)

Method - Part 1

JS Code

Complexity Analysis

CODING INTERVIEW QUESTION Insert Interval

Method - Part 1

Method - Part 2 (Walkthrough)

JS Code

CODING INTERVIEW QUESTION Non Overlapping Intervals

Method Part 3 - Why Greedy

Method Part 2 - Walkthrough

Method Part 1

Data Structures Crash Course Linked Lists

Coding Interview Q2 Remove Duplicates

Coding Interview Q1(Medium) Design a Singly Linked List

Javascript Code walkthrough

Method and Big O analysis

Coding Interview Q1(Easy) Reverse

Coding Interview Q2(Medium) Cycle Detection

Javascript Code walkthrough

Proof

Coding Interview Q1(Medium) Find duplicate number

method and Big O analysis

Coding Interview Q2(Medium) Add 2 numbers

method and Big O analysis

Coding Interview Q1 Remove Node, Insert Node

Method remove

Insert Intro

walkthrough remove

JavaScript code Remove

Method Insert

Remove Val Method

Insert at Position

Coding Interview Q2 Remove Value, Insert at Position in Doubly Linked List

JavaScript code Insert

method

Walkthrough Insert

JavaScript Code

Coding Interview Q1 Design a Stack

Data Structures Crash Course Stacks and Queues

Coding Interview Q2(Medium) Reverse Polish Notation

Coding Interview Q1 Design a Queue

Coding Interview Q2(Easy) Queue with Stack

method and Big O analysis

Data Structures Crash Course Trees Introduction

What is a BST - Binary Search Tree

Proof height of Balanced Binary tree is floor(log N)

Theory Binary Tree Terminaologies

Theory Binary Trees 1

Coding Interview Q1 Construct Binary Search Tree,Big O analysis

Javascript Code Walkthrough

Coding Interview Q2 Traverse - BFS and DFS,Big O analysis

Javascript Code Walkthrough

CODING INTERVIEW QUESTION Pre order Traversal of Binary Tree Iterative

JavaScript Code Preorder Traversal Iterative

CODING INTERVIEW QUESTION Inorder Traversal of Binary Tree - Iterative

Approach

JavaScript Code - Inorder Traversal of Binary Tree

CODING INTERVIEW QUESTION Post order traversal of Binary Tree - Iterative

JavaScript Code - Postorder Traversal of Binary Tree

CODING INTERVIEW QUESTION Path Sum 2

Coding Interview Q1(Medium) Level Order traversal

Insert method

Coding Interview Q2(Medium) Left Right view

Level Order Traversal Method and Big O analysis

Method and Big O analysis

JavaScript code

JavaScript code - Level order traversal

Iterative method and Big O analysis

Coding Interview Q1 (Easy) Invert Binary Tree

JavaScript Code Iterative

Recursive method and Big O analysis

Coding Interview Q2 (Easy) Diameter of Binary Tree

Method and Big O analysis

Coding Interview Q1(Easy) sorted array to BST

method and Big O analysis

Coding Interview Q2(Medium) Valid BST

JavaScript code

Method and Big O analysis

JavaScript Code

Binary Heap Data Structure Crash Course

Proof of Build Binary Heap Time Complexity

Coding Interview Q1 Construct Max Binary Heap, Big O analysis

Introduction to Priority Queue

Coding Interview Q2 Construct Priority Queue,Big O analysis

Data Structures Crash Course Graphs Introduction

Coding Interview Q1 BFS, Adjacency List,Big O analysis

Data Structures Crash Course Graphs - Part 2

Data Structures Crash Course Graphs - Part 3

BFS, Adjacency Matrix

Coding Interview Q2 DFS, Recursive, Big O analysis

DFS Iterative

JavaScript Code

Coding Interview Q2(Medium) Course Scheduler

Coding Interview Q1 Number of Components, Big O analysis

JavaScript Code

Brute Force Method and Big O analysis

Big O - Brute Force Method

JavaScript Code - Brute Force Method

Topological Sort based method and Big O analysis