Mastering Data Structures and Algorithms in Java: From Big O to Interview Success
Master essential data structures and algorithms in Java to ace technical coding interviews. Learn Big O complexity, dynamic programming, trees, graphs, and algorithmic patterns through comprehensive problem-solving techniques.

Course Overview
This in-depth curriculum delivers an exhaustive foundation in computer science fundamentals, data structures, and algorithmic problem-solving using Java. Designed specifically for software engineers preparing for competitive technical interviews, the course transitions from computational complexity theory into hands-on implementation and algorithmic pattern recognition.
What You'll Learn
- Complexity Analysis: Evaluate runtime and memory overhead using Big O, Big Omega, and Big Theta notations.
- Linear Data Structures: Build and manipulate dynamic arrays, linked lists, stacks, and queues from first principles.
- Non-Linear Structures: Traverse and balance binary trees, binary search trees (BST), heaps, tries, and disjoint-set unions (Union-Find).
- Graph Theory: Implement Breadth-First Search (BFS), Depth-First Search (DFS), Dijkstra's shortest path, and topological sorting.
- Advanced Problem-Solving: Formulate optimal subproblems with Dynamic Programming (memoization and tabulation), greedy heuristics, and backtracking.
- Interview Patterns: Recognize and execute two-pointer, sliding window, interval scheduling, bitwise manipulation, and fast-and-slow pointer techniques.
Pattern Spotlight: Two-Pointer Traversal
public class TwoPointerSearch {
// O(n) time complexity and O(1) auxiliary space
public static boolean hasTargetSum(int[] sortedArray, int target) {
int left = 0;
int right = sortedArray.length - 1;
while (left < right) {
int sum = sortedArray[left] + sortedArray[right];
if (sum == target) {
return true;
} else if (sum < target) {
left++;
} else {
right--;
}
}
return false;
}
}
Prerequisites
- Working knowledge of basic programming fundamentals and core Java syntax (variables, control flow, methods, and classes).
- Foundational familiarity with basic high-school algebra and discrete mathematics concepts.
Tools & Technologies
- Programming Language: Java (JDK 17+ recommended)
- Development Environment: IntelliJ IDEA, Eclipse, or Visual Studio Code
- Version Control: Git and GitHub for tracking problem solutions and implementations
Course Content
Algorithmic Complexity and Technical Interview Fundamentals
Technical Interviews 101: Structure, Mindset, and Communication
Mastering Big O Notation and Code Block Time Complexity Analysis
Space Complexity Analysis and Core Data Structure Taxonomies
Array Manipulation, Two Pointers, and Sliding Window
Mastering Array Fundamentals and In-Place Manipulation
Implementing Fixed and Dynamic Sliding Window Algorithms
Solving Complex Problems with Two-Pointer Strategies
String Algorithms, Sorting, and Binary Search
Mastering String Manipulation and Pattern Matching in Java
Classical Sorting Algorithms and Binary Search Optimization
Linked Lists, Stacks, Queues, and Priority Queues
Mastering Linked Lists: Pointer Manipulation, Reversal, and Cycle Detection
Stack Fundamentals: Monotonic Stacks, Expression Evaluation, and LIFO Patterns
Queues and Double-Ended Queues: FIFO Processing and Buffer Architectures
Priority Queues and Binary Heaps: Custom Comparators and Top-K Selection
Tree Structures and Binary Search Trees
Tree Fundamentals and Depth-First Traversal Strategies
Breadth-First Search, Level-Order Traversal, and Tree Metrics
Binary Search Tree Operations, Validation, and Lowest Common Ancestor
Graph Algorithms and Traversal Strategies
Graph Representations and Fundamental Traversals: BFS and DFS
Cycle Detection, Topological Sort, and Kahn's Algorithm
Shortest Path Algorithms and Disjoint Set Union (Union-Find)
Dynamic Programming and Greedy Paradigms
Mastering Dynamic Programming: Memoization, Tabulation, and State Transitions
Greedy Algorithms: Optimal Substructure and Local Choice Heuristics
Backtracking, Intervals, and Matrix Manipulation
Mastering Interval Patterns: Merging, Insertion, and Overlap Resolution
Combinatorial Backtracking: State Space Trees, Subsets, and Pruning Strategies
Matrix Traversal and In-Place Two-Dimensional Transformations
Bit Manipulation, Mathematical Algorithms, and Object-Oriented Design
Solving Mathematical and Geometric Problems in Java
Designing Object-Oriented Systems and Interview Data Structures
Mastering Bit Manipulation and Low-Level Binary Logic
This course includes
- 49h 44m on-demand video
- 26 lessons across 9 chapters
- 9 interactive quizzes
- Access on mobile and desktop
- Source playlist on YouTube
About the Channel
Learn math, programming, and computer science for free. A 501(c)(3) tax-exempt charity. We also run a free learning interactive platform at freecodecamp.org
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