CS 251: Data Structure and Algorithms

Designed to help understand the fundamentals of DS & Algorithms really well. Technical interviews follow a pattern. If you know the pattern, you’ll be a step ahead of the competition and learn in Java. You will answer practice problems & quizzes.

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Course Curriculum

1. Introduction
1. Introduction to Java
2. Getting Started
3. The Next Step
4. Final Thoughts
5. Online Compilers
6. Lesson Summary
1. Java Statements
2. Java Methods
3. Java Exceptions
4. Lesson Summary
5. Quiz 1.2
1. While Loop
2. While Loop Example
3. Indefinite While Loop
4. Off by One
5. Infinite Loop
6. Lesson Summary
7. Quiz 1.3
1. Steps to Writing a Program
2. Writing Code
3. Syntax
4. Online Compilers
5. Testing
6. Debugging
7. Lesson Summary
8. Quiz 1.4
1. Defining Pseudocode
2. Understanding Pseudocode
3. Examples of Pseudocode
4. Basic Guidelines
5. Pseudocode Text Editors
6. Lesson Summary
7. Quiz 1.5
1. Comments in Your Code
2. Single Line Comments
3. Multi-Line Comments
4. Documentation Comments
5. Lesson Summary
6. Quiz 1.6
1. Introduction
1. A World of Objects
2. Classes and Objects
3. Inheritance
4. Encapsulation, Interfaces, Methods
5. Polymorphism
6. Lesson Summary
7. Quiz 2.1
1. What Is an Object in Programming?
2. Classes and Objects
3. Methods and Functions
4. OOP Concepts
5. Lesson Summary
6. Quiz 2.2
1. A Great Inheritance
2. Syntax
3. Inheritance in Java: Example
4. Overriding
5. Lesson Summary
6. Quiz 2.3
1. Interfaces and Abstract Classes
2. Interfaces
3. Multiple Inheritance
4. Classes Using Interfaces
5. Extend vs. Implement
6. Abstract Classes
7. Lesson Summary
8. Quiz 2.4
1. What is an Abstract Data Type?
2. Abstraction
3. Lesson Summary
4. Quiz 2.5
1. Creating a Data Type
2. Abstraction
3. Lesson Summary
4. Quiz 2.6
1. Error! Error!
2. Exception Types
3. Java Classes
4. Exceptions: Examples
5. Divide By Zero
6. Array Out Of Bounds
7. Handling Exceptions
8. Lesson Summary
9. Quiz 2.7
1. Nested Classes
2. Defining Static
3. Uses for Static Nested Classes
4. Lesson Summary
5. Quiz 2.8
1. Inner Classes
2. Types of Inner Classes
3. Non-Static Nested Class
4. Local Classes
5. Static Nested Class
6. Shadowing
7. Lesson Summary
8. Quiz 2.9
1. Introduction
1. Arrays
2. Basic Array
3. Everything Starts at Zero!
4. Length is Fixed
5. Multiple Dimensions!
6. Examples
7. Prefilling and Displaying the Array
8. The User Name
9. Lesson Summary
10. Quiz 3.1
1. Arrays
2. Sorting
3. java.util.Arrays
4. Lesson Summary
5. Quiz 3.2
1. Multidimensional Arrays
2. Creating Multidimensional Arrays
3. Populating Multidimensional Arrays
4. Processing Arrays
5. 3D Arrays
6. Lesson Summary
7. Quiz 3.3
1. The Linked List Data Structure
2. Singly Linked List
3. Doubly Linked List
4. Circular Linked List
5. Comparison to an Array
6. Linked List Methods
7. Lesson Summary
8. Quiz 3.4
1. Linked Lists vs. Arrays
2. Singly Linked Lists
3. Create a Linked List in Java
4. Add to a List
5. Add to the Beginning (or End)
6. Remove Items
7. Linked List Methods
8. Lesson Summary
9. Quiz 3.5
1. Circularly Linked Lists
2. Implementing in Java
3. Create the Java File
4. Update CircularLinkedList
5. Update The Node Class
6. Print Function
7. Add Node to Head
8. Update Main
9. Add Node to Tail
10. Round Robin
11. Remove an Element
12. Delete Node from Head
13. Lesson Summary
14. Quiz 3.6
1. Doubly Linked Lists
2. Nodes
3. Uses for a Doubly Linked List
4. Practical Example
5. Create the DoubleLists Class
6. Add To Head
7. Add To Tail
8. Insert a Node at a Given Element
9. Print
10. Lesson Summary
11. Quiz 3.7
1. Array Comparison
2. What does Not Work
3. What Works
4. Further Elaboration
5. Challenges with Equivalency Testing in Object Oriented Design
6. Example:
7. Effect of Type casting on Equivalency Testing
8. Effect of Method Overload on Equivalency Testing
9. Effect of Method Override on Equivalency Testing
10. Effect of custom instance Methods on Equivalency Testing
11. Lesson Summary
12. Quiz 3.8
1. Cloning an Array
2. Clone vs Copy?
3. Cloning
4. Multi-Dimensional Arrays
5. Lesson Summary
6. Quiz 3.9
1. Introduction
1. What Is a Programming Algorithm?
2. Programming Algorithm Example
3. Lesson Summary
4. Quiz 4.1
1. Algorithm Analysis
2. Experimental Analysis of Algorithms
3. Limitations of Experimental Studies
4. Asymptotic Analysis
5. Lesson Summary
6. Quiz 4.2
1. Analysis of Algorithmic Functions
2. Constant Function f(n) = c or O(1)
3. Logarithmic Function f(n) = log n or O log (n)
4. Linear Function or Linear Time Complexity O(n)
5. N-log-N function or O(n log n)
6. Quadratic Function or O(n2)
7. Cubic and Polynomials or O(nn)
8. Exponential Function
9. Lesson Summary
10. Quiz 4.3
1. Big-O notation
2. Time and Space Complexity
3. O(1)
4. O(N)
5. O(N^2)
6. O(2N)
7. Lesson Summary
8. Quiz 4.4
1. Simple Justification Techniques for Algorithm Analysis
2. Why Analyze an Algorithm?
3. Algorithmic Complexity
4. Algorithmic Methods
5. Quiz 4.5
6. Lesson Summary
1. Introduction
1. Recursion & Iteration
2. Recursion
3. Iteration
4. Name Reversal Example:
5. Factorial Example
6. The Differences
7. Lesson Summary
8. Quiz 5.1
1. Recursion: Calling Yourself
2. Factorials
3. Fibonacci Series
4. Tower of Hanoi
5. Lesson Summary
6. Quiz 5.2
1. Binary Search
2. Sorted Array Binary Search
3. Full Binary Search Code
4. Main Method to Call the Search
5. Unsorted Array Binary Search
6. Lesson Summary
7. Quiz 5.3
1. Complexity Analysis of Algorithms
2. Time Complexity of Algorithms
3. Space Complexity
4. Fibonacci Sequence Example
5. Lesson Summary
6. Quiz 5.4
1. Sequential Search
2. The Sequential Search Algorithm
3. Sample Search Assumptions
4. Sample Search Steps
5. Implementing a Sequential Search in Java
6. Big O Notation
7. Lesson Summary
8. Quiz 5.5
1. How Does Binary Search Work?
2. The Algorithm
3. Example
4. Java Implementation of Binary Search
5. Performance
6. Lesson Summary
7. Quiz 5.6
1. Exponential Search
2. Java Code
3. Big O Notation
4. Lesson Summary
5. Quiz 5.7
1. Lesson Overview & Knowledge Required
2. Program Code
3. Code Application
4. Follow-Up Questions
5. Answer Key
6. Code Application
7. Follow-Up Questions
1. Introduction
1. Stacks
2. What Can You Do with a Stack?
3. Java Code
4. Access Elements in the Stack
5. Lesson Summary
6. Quiz 6.1
1. Introduction
2. The Queue Interface
3. Implementing a Queue
4. Advance Considerations
5. Lesson Summary
6. Quiz 6.2
1. What is a Double-Ended Queue?
2. Practical Application
3. Working with a Deque in Java
4. Scenario 1: Status Equals 1
5. Scenario 2: Status Equals 0
6. Scenario 3: Status Equals -1
7. Adding a Priority Widget to the Front of the Line
8. Lesson Summary
9. Quiz 6.3
1. Introduction
2. Program Code
3. Code Application
4. Follow-Up Questions
5. Code Application
1. Introduction
1. Dynamic Arrays
2. Dynamic Arrays: Getting Started
3. Creating a Class
4. ArrayList
5. Lesson Summary
6. Quiz 7.1
1. Abstract Data Type (ADT)
2. The Positional List ADT in Java
3. Creating a Positional List
4. Accessing Nodes in the List
5. Lesson Summary
6. Quiz 7.2
1. Java Sets
2. Creating & Iterating in the Set
3. A Different Set
4. Lesson Summary
5. Quiz 7.3
1. Introduction to the Java Collections Framework
2. The List Interface
3. Working with Lists
4. Searching and Sorting Lists
5. Algorithms for Lists
6. Lesson Summary
7. Quiz 7.4
1. An Introduction to Positional Lists
2. Working with Positional Lists
3. Instantiating a Positional List
4. Adding Data to a Positional List
5. Getting Data From Our List
6. Iterating Through a List
7. Sorting a Positional List
8. Lesson Summary
9. Quiz 7.5
1. Introduction
1. What is a Tree?
2. Tree Terminology
3. Common Operations
4. Insert
5. Search
6. Lesson Summary
7. Quiz 8.1
1. What Is a Binary Tree?
2. Types & Implementation
3. Traversing Binary Trees
4. Binary Search Tree
5. Application
6. Lesson Summary
7. Quiz 8.2
1. Tree Data Structures
2. Comparison of Trees in Data Structure
3. Strengths and Weaknesses
4. Applications
5. Lesson Summary
6. Quiz 8.3
1. Introduction
2. Lesson Overview and Knowledge Required
3. Program Code
4. Code Application
5. Follow-Up Questions
6. Code Application
1. Introduction
1. What is a Priority Queue?
2. Creating Order in a Priority Queue
3. Creating a Patient Class
4. Creating the Implementing Class
5. Additional Methods
6. Lesson summary
7. Quiz 9.1
1. Why use a Priority Queue?
2. Priority Queue Implementation with an Unsorted List
3. Priority Queue Implementation with a Sorted List
4. Comparing Implementation Methods
5. Lesson Summary
6. Quiz 9.2
1. What is a Heap Data Structure?
2. Min-Heap vs. Max-Heap
3. Properties of a Heap Tree
4. Ordering
5. Structure
6. Applications of Heap
7. Heap Sort
8. Graph Algorithms
9. Priority Queue
10. Lesson Summary
11. Quiz 9.3
1. The Need for Priority Queues
2. Implementing a Priority Queue for Tickets
3. Creating a Driver Class
4. Sorting by Multiple Elements
5. Summary
6. Quiz 9.4
1. Introduction
1. Map Data Type
2. Map Data Type Characteristics
3. When You Use Map Data Type
4. Map Data Type (Java) Methods
5. Lesson Summary
6. Quiz 10.1
1. Hash Tables
2. Hashing
3. Collisions
4. Hash Functions
5. Collision Resolution
6. Linked Lists
7. Open Addressing
8. A Hash Table Example
9. Lesson Summary
10. Quiz 10.2
1. Robin Hood: "Stealing" Keys
2. Save Us, Robin Hood!
3. Benefits of Robin Hood
4. What if Nothing is Found?
5. Organ-Pipe Searching and Smart Search
6. Lesson Summary
7. Quiz 10.3
1. Sorted Maps
2. Automatic Ordering using TreeMap
3. Finding the First Entry and the Last Entry
4. Floor Key and Ceiling Key
5. Higher Key and Lower Key
6. Extracting a Sub-Map from the Map
7. Lesson Summary
8. Quiz 10.4
1. What Is Separate Chaining?
2. Concept
3. Advantages
4. Disadvantages
5. Lesson Summary
6. Quiz 10.5
1. Lesson Overview and Knowledge Required
2. Program Code
3. Output
4. Code Application
5. Follow-up Questions
6. Follow-up Questions Answer Key
7. Code Application Answer Key
1. Introduction
1. What is a Binary Search Tree?
2. Binary Search Tree: Sort Maps
3. Binary Search Tree: Representation
4. BST Operations
5. BST: Search
6. BST: Add a Node
7. BST: Remove a Node
8. Lesson Summary
9. Quiz 11.1
1. What are AVL Trees?
2. AVL Tree Characteristics
3. The Balance Factor
4. Rotations
5. Insertion
6. Deletion
7. Applications and Uses
8. Lesson Summary
9. Quiz 11.2
1. Splay Trees
2. Splay Tree Operations
3. Zig
4. Zig-Zag
5. Zig-Zig
6. Performance
7. Splay Tree Java Code
8. Lesson Summary
9. Quiz 11.3
1. What Are Search Trees?
2. Multiway Search Trees
3. 2-3-4 Trees
4. Red-Black Trees
5. Lesson Summary
6. Quiz 11.4
1. What are Search Algorithms?
2. Search Algorithms and Big O Notation
3. Speed
4. Binary Search Tree (BST)
5. AVL Trees
6. Splay Tree
7. Red-Black Trees
8. Multiway Tree
9. 2-3-4 Trees
10. Lesson Summary
11. Quiz 11.5
1. Assignment Description
2. Assignment Overview & Knowledge Required
3. Program Code
4. Code Application | Question
5. Follow-Up Questions
6. Follow-Up Questions
7. Code Application
1. Chapter 11 assignment - Red & Black trees
1. Introduction
1. Bubble Sort
2. Arrays
3. Bubble Sort Java Program
4. Results
5. Performance
6. Lesson Summary
7. Quiz 12.1
1. Selection Sort Algorithm
2. Implementation
3. Performance and Usage
4. Lesson Summary
5. Quiz 12.2
1. Merge Sort
2. Algorithm
3. Implementation
4. Output
5. Performance
6. Lesson Summary
7. Quiz 12.3
1. Sorting
2. Quick Sort
3. Algorithm
4. Pseudocode
5. Java Implementation
6. Performance
7. Lesson Summary
8. Quiz 12.4
1. Sorting Arrays
2. Implementation in Java
3. Performance and Big-O Notation
4. Check the Processing Time
5. Lesson Summary
6. Quiz 12.5
1. What are Sorting Algorithms?
2. The Big-O Notation
3. Bubble Sort Algorithm
4. Bubble Sort: Method
5. Bubble Sort: Performance
6. Selection Sort Algorithm
7. Selection Sort Method
8. Selection Sort: Performance
9. Merge Sort Algorithm
10. Merge Sort Method
11. Merge Sort: Performance
12. Quick Sort Algorithm
13. Quick Sort: Performance
14. Insertion Sort Algorithm
15. Insertion Sort: Performance
16. Lesson Summary
17. Quiz 12.6
1. What is Open Addressing?
2. The Rules of Open Addressing
3. Linear Probing
4. Quadratic Probing
5. Double Hashing
6. Lesson Summary
7. Quiz 12.7
1. Lesson Overview and Knowledge Required
2. Program Code
3. Code Application
4. Follow-Up Questions
5. Code Application
1. Introduction
1. Text as a Data Structure
2. Strings are Immutable!
3. Convert to a Character Array
4. Convert an Array to a String
5. StringBuilder: The Immutable is Mutable
6. Lesson Summary
7. Quiz 13.1
1. String Searching Algorithms
2. Brute Force Algorithm
3. Boyer-Moore Algorithm
4. Knuth-Morris-Pratt Algorithm (KMP)
5. Building the Longest Proper Prefix Array (lps)
6. Lesson Summary
7. Quiz 13.2
1. Introduction
2. Implementing Trie Operators
3. Adding a String to a Trie
4. Searching a Trie
5. Advanced Trie Concepts
6. Lesson Summary
7. Quiz 13.3
1. Greedy Algorithm
2. Huffman's Code
3. Fixed Length vs Variable Length Coding
4. Why is Huffman's Code Greedy?
5. Huffman's Code Implementation
6. Quiz 13.4
7. Lesson Summary
1. Introduction
1. A Graph
2. Vertices
3. Edges
4. Paths and Others
5. Lesson Summary
6. Quiz 14.1
1. Graph Theory
2. A Graph
3. Vertices
4. Edges
5. Loops
6. Lesson Summary
7. Quiz 14.2
1. Simple vs. Weighted Graph
2. Directed vs. Undirected Graph
3. What is a Directed Graph?
4. What is an Undirected Graph?
5. Weighted Directed Graph and Undirected Graph
6. Graph Representation
7. Adjacency Matrix
8. Adjacency List
9. Dijkstra's Algorithm
10. Lesson Summary
11. Quiz 14.3
1. Shortest Path Problem
2. Dijkstra's Algorithm
3. History of Dijkstra's Algorithm
4. Basics of Dijkstra's Algorithm
5. Dijkstra's Algorithm Example
6. Dijkstra's Algorithm Pseudocode
7. Lesson Summary
8. Quiz 14.4
1. Graphs in Discrete Mathematics
2. Types of Graphs
3. Uses of Graphs: Example 1
4. Example 2
5. Lesson Summary
6. Quiz 14.5
1. Data Structure
2. Linear & Non-Linear Data Structures
3. Graph Data Structure
4. Cyclic and Acyclic Graphs
5. Dense and Sparse Graphs
6. Lesson Summary
7. Quiz 14.6
1. Lesson Description
2. Lesson Overview and Knowledge Required
3. Program Code
4. Code Application
5. Follow-Up Questions
6. Code Application
1. Introduction
1. Java Memory Management
2. Stack Memory
3. Heap Memory
4. Garbage Collection
5. Code Example
6. Lesson Summary
7. Quiz 15.1
1. Cache Memory & Related Definitions
2. CPU Cache
3. How the CPU Cache Works
4. Multi-Level Caches
5. Lesson Summary
6. Quiz 15.2
1. What is External Searching?
2. What are B-Trees?
3. B-Tree Characteristics
4. Memory Management in B-Trees
5. Searching Using B-Trees
6. Disadvantages
7. Example
8. Lesson Summary
9. Quiz 15.3
1. Internal & External Memory
2. Internal & External Memory Sorting
3. Multi-Way Merging
4. Lesson Summary
5. Quiz 15.4
1. Assignment
2. Final Exam

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Ch 1 - Basics of Java

Ch 1.1 - How to Setup a Coding Environment for Programming in Java

Ch 1.2 - Java Statements: Definition & Examples

Ch 1.3 - While Loops in Java: Example & Syntax

Ch 1.4 - How to Write a Program: Coding, Testing & Debugging

Ch 1.5 - Pseudocode: Definition & Examples

Ch 1.6 - Comments in Java: Syntax & Example

Ch 2 - Object-Oriented Design Fundamentals

Ch 2.1 - Five Basic Concepts of Object-Oriented Design

Ch 2.2 - Object-Oriented Programming: Objects, Classes & Methods

Ch 2.3 - Inheritance in Java: Definition, Example & Syntax

Ch 2.4 - Comparing Interfaces & Abstract Classes in Java

Ch 2.5 - Abstract Data Types

Ch 2.6 - Abstract Data Types in Java

Ch 2.7 - Exceptions in Java: Definition & Example

Ch 2.8 - Static Nested Classes in Java: Definition & Example

Ch 2.9 - Inner Classes in Java: Definition & Example

Ch 3 - Core Data Structures

Ch 3.1 - What is an Array in Java?

Ch 3.2 - How to Sort an Array in Java

Ch 3.3 - Java: Multidimensional Arrays

Ch 3.4 - Linked List Methods & Examples

Ch 3.5 - Singly Linked Lists in Java: Creation & Application

Ch 3.6 - Circularly Linked Lists in Java: Creation & Uses

Ch 3.7 - Doubly Linked Lists in Java: Creation & Nodes

Ch 3.8 - Equivalency Testing Using Arrays in Java

Ch 3.9 - How to Clone an Array in Java

Ch 4 - Analyzing Algorithms

Ch 4.1 - What is an Algorithm in Programming? - Definition, Examples & Analysis

Ch 4.2 - What Is Algorithm Analysis? - Methods & Types

Ch 4.3 - Seven Experimental Functions in Algorithm Analysis

Ch 4.4 - Big-O Notation in Algorithm Analysis: Principles & Use

Ch 4.5 - Simple Justification Techniques for Algorithm Analysis

Ch 5 - Recursion & Recursive Algorithms

Ch 5.1 - Methods for Recursion vs. Iteration in Java

Ch 5.2 - Recursion in Java: Application & Examples

Ch 5.3 - Using Recursion in Java for Binary Search

Ch 5.4 - Analysis of Recursive Algorithms

Ch 5.5 - Sequential Search in Java: Algorithm, Implementation & Analysis

Ch 5.6 - Binary Search in Java: Algorithm, Implementation & Analysis

Ch 5.7 - Exponential Search in Java: Algorithm, Implementation & Analysis

Ch 5.8 - Practical Application for Data Structures: Recursion in Java

Ch 6- Stacks, Queues & Lists in Java

Ch 6.1 - Stack Data in Java: Functionality & Class

Ch 6.2 - Queue Data in Java: Definition & Functions

Ch 6.3 - Double-Ended Queues in Java: Use & Interface

Ch 6.4 - Practical Application for Data Structures: Stacks, Queues & Linked Lists

Ch 7 - List & Iterator Abstract Data Types

Ch 7.1 - Java: Dynamic Arrays

Ch 7.2 - Positional Lists in Java: Definition & Access

Ch 7.3 - How to Iterate Set in Java

Ch 7.4 - Java Collections Framework: Methods & Algorithms

Ch 7.5 - How to Sort a Positional List in Java

Ch 8 - Trees in Data Structure

Ch 8.1 - Trees in Data Structures: Methods & Examples

Ch 8.2 - Binary Trees: Applications & Implementation

Ch 8.3 - Comparing Trees in Data Structure: Strengths & Weaknesses

Ch 8.4 - Practical Application for Data Structures: Trees

Ch 9 - Priority Queues in Java

Ch 9.1 - Priority Queue: Definition & Methods

Ch 9.2 - How to Implement Priority Queues in Java

Ch 9.3 - Heap Data Structure: Definition & Properties

Ch 9.4 - How to Sort with a Priority Queue in Java

Ch 10 - Maps & Hash Tables in Data Structures

Ch 10.1 - Maps in Data Structures: Definition & Methods

Ch 10.2 - Hash Tables: Definition, Use & Functions

Ch 10.3 - Robin Hood Hashing: Concepts & Algorithms

Ch 10.4 - Sorted Maps in Data Structures: Definition & Overview

Ch 10.5 - Separate Chaining: Concept, Advantages & Disadvantages

Ch 10.6 - Practical Application for Data Structures: Hash Tables

Ch 11 - Search Trees & Types

Ch 11.1 - Binary Search Trees: Definition & Uses

Ch 11.2 - AVL Trees: Implementation & Uses

Ch 11.3 - Splay Trees: Definition & Applications in Java

Ch 11.4 - Multiway Search, 2-3-4 & Red-Black Trees: Operations & Overview

Ch 11.5 - Strengths & Weaknesses of Different Search Algorithms

Ch 11.6 - Assignment & Practical Application for Data Structures: Search Trees

Chapter 11's assignment

Ch 12 - Sorting & Selection in Java

Ch 12.1 - Bubble Sort in Java: Functionality, Implementation & Performance