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Mahmut SalmanAlgorithms & DSA

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2025

From Length to Sequences: Backtracking Through the LCS Table
Cracking Longest Common Subsequence: A Journey from Confusion to Clarity
The LCA Revelation: When Return Values Tell a Story
Why Greedy Fails: Discovering Dynamic Programming Through Coins
The LRU Cache Puzzle: Discovering Why We Need HashMap + LinkedList
Discovering Binary Tree Width: A Journey from HashMap to Position Formulas
Why Can't I Do new List<>()? Understanding Interfaces vs Concrete Classes
Finding K-Sum Subarrays: A Journey from Confusion to Clarity
Why Won't My Selected Row Turn Blue? The Hover vs Selection Mystery
Git's Asterisk Won't Go Away: Understanding 'deleted:' in Git Status
Why Not Just Use a Loop? Understanding When Prefix Sum Actually Matters
Java Arrays of Generics - Set[] and HashSet[] Explained
My Div Says 'Test' But Takes Up the Whole Width? Understanding Block Elements and Content Size
I Have Multiple Changes But Only Want to Commit the Port Update—My Git Partial Staging Journey
Wait, I Only See h-48 for Height—Where's the Width? Understanding How CSS Grid Automatically Sizes Cards
I Copied [responsive-columns] Literally and It Didn't Work! Understanding Placeholders vs Real Code
How Does This Badge Work? Understanding CSS Class Order and the relative-absolute Pattern
Wait, What's [&_button] in Tailwind? Understanding &, >, and _ Selectors for Nested Elements
How Do I Know My Grid Actually Works? Testing Responsive Layouts with Colorful Placeholders
Fast-Forward Merge vs Rebase: Which One Should You Use? 🤔
Git Worktree Mystery: Why Isn't My Postman Folder Ignored? 🔍
Why Do I Need Force Push After Rebase? 🚀
Wait, My Main Branch Doesn't Have My Changes? 🤯 Understanding Rebase vs Merge
Git Worktree Trick: Merge Without Checkout! 🪄
Git Rebase Logic: Why Can't I Just Merge? 🤔
Git Rebase Success: From 'Why Rebase?' to Clean Linear History! 🎉
Git Worktree Magic: Do Commits Show Up in Other Worktrees? 🪄
Git Rebase's Two-Phase Mystery: Why Isn't It Just a Merge? 🤔
Why Can't I Just Use Regular Variables? Understanding useState's Magic
Wait, Does 'await' Make My Code Synchronous? Understanding Async/Await's Double Nature
I Only Added w-full, Why Is My Button Text Centered? Understanding Browser Defaults
Wait, My Buttons Are Still Side-by-Side Without Flex? Understanding inline-block vs Flexbox
Wait, Why Does My Width Stay 384px But Height Changes? Understanding the CSS Box Model
Why Adding 'block' to My Label Changed Everything: Understanding CSS Display Property
Why My Password Field Wasn't Spacing Correctly: Understanding Form Structure and space-y
The Mystery of CSS Flexbox Centering: Why Merging Two Divs Breaks Everything
From HTML Error Pages to Beautiful JSON: Fixing JWT Authentication Errors in Spring Boot
Stop Writing For Loops: Master Java Streams with 5 Essential Patterns
Mastering Two-Tier Exception Handling in Spring Boot: A Complete Guide
Wait, You're Exposing Your Password?! Understanding Input vs Output DTOs in Spring Boot
The Mystery of the 403 Login: Understanding Spring Security's Two-Stage Authentication
My 'Aha!' Moment: Why Public/Private Actually Matters (And I Was Wrong About Security)
Why Create Custom Exceptions? It's Not Just About the Name!
Dev vs Prod: Why You Can't Store Secrets in Files on Production Servers
Factory Pattern: From Scattered If-Else Hell to Zero Conditionals
Why My Object Changes Don't Stick: In-Memory vs Database Persistence
Interfaces Beyond Frameworks: 7 Real-World Scenarios You'll Actually Use
Why Private Fields with Public Setters? Understanding Encapsulation and Long vs long
Java Streams: Understanding .stream(), .map(), and .collect()
Why Two Methods for JWT Token Generation? Understanding Single Responsibility Principle
Is It Safe to Send Passwords in Login Requests? HTTP vs HTTPS Security
ResponseEntity<T>: The Delivery Box That Can Hold Anything
Classes vs Interfaces in Java: The Deep Dive (Part 2)
The Deep OOP Principles: Why Interfaces Aren't Just About Code Reuse (Part 3)
But Someone Still Has to Write the Code, Right? The Truth About Frameworks (Part 4)
Spring Data JPA Part 5: Why UserRepository MUST Be an Interface - Java Type System Rules
Why Spring Data JPA Repositories Must Be Interfaces, Not Classes
Why Spring Security Locks All Endpoints Just By Adding the Dependency
H2 Console Works But No Tables? Troubleshooting Spring Boot Database Setup
Utility Classes vs Interfaces: Why Static Methods Aren't Enough
The Magic of @Entity: How One Annotation Creates Database Tables
Type-Safe User Roles: Using Enums in JPA Entities
Git Merge vs Rebase vs Squash: Which One Should You Use?
Time Travel in Git: How to Add Code to Past Commits and Affect All Future Ones
What Happens If You Don't Use Package Declarations in Java?
JWT in Spring Boot: The Three Dependencies You Need
Maven Dependency Magic: Why Adding 2 Dependencies Downloads 50+ JARs (And Where They Go)
Database Locked: The Multiple Spring Boot Processes Problem
Spring Boot Database Configuration: What Happens When Your App Starts
Why Moving a Spring Boot Project Breaks Dependencies (And How to Fix It)
Mastering Dynamic Programming: From 0/1 Knapsack to Partition Problems
Must-Read Insights: Key Moments in My Learning Journey
Wait, Is This Actually DP? A Conversation About Memoization
When DP Gets Messy: A Student's Journey Through Delete and Earn
The Dynamic Programming Learning Journey: A Conversation

2024

Understanding Java Variable Scoping - Why Can I Reuse Variable Names?
Mastering Docusaurus Tabs - Interactive Content Examples
Remove Linked List Elements - Mastering Pointer Manipulation
Mastering Minimum Subarray Sum with Sliding Window Technique
Finding Maximum Depth of Binary Tree - DFS vs BFS Approaches
Solving LeetCode - Length of Last Word in Java

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Mahmut Salman
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