Java 8 LinkedList Sum Problem Solution

💻 Day 23 – Strings in Java Today I explored Strings in Java, one of the most fundamental and important concepts. I learned about different types of string handling: 🔹 String – Immutable (cannot be changed) 🔹 StringBuilder – Mutable and faster 🔹 StringBuffer – Mutable and thread-safe Understanding immutability was a key highlight today, as it plays an important role in memory management and performance. 💡 Key takeaway: Choosing the right type of string handling improves both performance and efficiency in Java applications. Continuing to strengthen my core Java concepts step by step 🚀 #Java #Strings #Programming #LearningInPublic #CodingJourney #Day23

Multithreading in Java finally clicked for me when I stopped memorizing it… and started visualizing it. 🧠 Here’s the simplest way to understand it: Imagine your application is doing only ONE task at a time. ➡️ Slow ➡️ Blocking ➡️ Poor performance Now introduce multithreading 👇 Multiple tasks run simultaneously: ✔ One thread handles API requests ✔ One processes data ✔ One writes logs Result? Faster and more efficient applications 🚀 But here’s what I learned the hard way: Multithreading is powerful… but dangerous if not handled properly. Common issues I faced: Race conditions Deadlocks Unexpected bugs What helped me: ✔ Proper synchronization ✔ Understanding thread lifecycle ✔ Using ExecutorService instead of manual threads Lesson: Multithreading is not just about speed — it’s about control and correctness. 💬 Have you faced any tricky bugs with multithreading? #Java #Multithreading #BackendDevelopment #SoftwareEngineering #Coding

Starting a 100-day Java series, and this is day 1 ☕ Today, we are covering Java variables - from syntax to scope to memory, all in one place. Declaration, data types, the 3 types of variables, casting, the final keyword and the mistakes most beginners make without realising. 10 slides covering everything. The last slide has a full cheat sheet worth saving.🔖 For more such tech content, follow @herbrewcode on Instagram too. #Java #Day1 #100DaysOfCode #LearnToCode #CodingJourney #HerBrewCode

🚀 Beats 100% of all Java solutions on LeetCode! Just solved LeetCode #290 — Word Pattern in Java with 0ms runtime, outperforming every submission. Here's how I approached it 👇 🧩 Problem: Given a pattern (like "abba") and a string of words, check if the words follow the exact same pattern — a full bijection. e.g. pattern = "abba", s = "dog cat cat dog" → true ✅ 💡 My approach: Used a single HashMap<Character, String> to map each pattern character to its corresponding word. The key insight: also check containsValue() to prevent two different characters from mapping to the same word — ensuring true one-to-one bijection. 📊 Results: Runtime: 0 ms — Beats 100.00% 🌿 Memory: 42.65 MB — Beats 80.14% 🔑 Key takeaway: Always verify bijection in both directions — a one-way map is not enough for pattern matching problems. One extra containsValue() check is all it takes! All 44 test cases passed ✅ — Clean, simple, and blazing fast. #LeetCode #Java #DSA #CodingChallenge #ProblemSolving #100Percent #Programming #SoftwareEngineering #CompetitiveProgramming #HashMap

#TapAcademy #Java #Fullstackdeveloment #Strings Strings in Java are used to store and handle text data. They are created using double quotes. For example, String text = "Hello, World!". Java offers many useful string methods, such as concat(), substring(), and toUpperCase(). You can compare, join, and format strings with these built-in methods. Strings are commonly used for managing text input, output, and data processing in programs.

🚀 Day 13 – Decimal to Binary Conversion & Scope in Java Today, I learned how to convert a decimal number into a binary number and also understood the concept of scope in Java. First, I studied the method of converting decimal to binary using repeated division by 2. For example, when converting the number 7, we divide it by 2 continuously and note the remainders. When we read the remainders in reverse order, we get the binary value (111). This method helped me clearly understand how binary numbers are formed. I also learned the logic behind writing this program using a while loop. In each iteration, we divide the number by 2, store the remainder, and increase the power value. This step-by-step process makes it easy to convert any decimal number into binary using code. Next, I revised the concept of scope, which tells where a variable can be accessed in a program. I learned about method scope, where variables declared inside a method can only be used within that method. Then, I understood block scope, where variables declared inside a block (like inside curly braces {}) are limited only to that block. I also saw examples showing correct and incorrect usage of variables, which made the concept much clearer. 💪 I will continue practicing daily and improve step by step. #Java #DSA #CodingJourney #Learning #Consistency

Day 92 - LeetCode Journey Solved LeetCode 143: Reorder List in Java ✅ This problem looks tricky at first, but once you break it into steps, it becomes clean and elegant. The idea is simple: 1️⃣ Find the middle of the list (slow-fast pointers) 2️⃣ Reverse the second half 3️⃣ Merge both halves alternately That’s it. Three steps, one solid solution. Key takeaways: • Mastering slow & fast pointer technique • In-place reversal of linked list • Merging two lists efficiently • Breaking complex problems into smaller parts ✅ All test cases passed ⚡ O(n) time and O(1) space Problems like this build real confidence in linked lists 💯 #LeetCode #DSA #Java #LinkedList #ProblemSolving #CodingJourney #InterviewPrep #Consistency #100DaysOfCode

📒 Day 27: final Keyword in Java 🔥 Java’s way of saying: “Modify me? Compile error loading…” 😎 In Java, the final keyword is used to apply restrictions on variables, methods, and classes to ensure immutability and controlled usage in object-oriented programming. 👉 Uses of final keyword: » 🔹 final variable → value cannot be changed once assigned » 🔹 final method → cannot be overridden in a subclass » 🔹 final class → cannot be extended or inherited 💡 Conclusion: The final keyword helps in achieving security, consistency, and controlled design in Java applications. #Java #CoreJava #OOP #Programming #Coding #LearnInPublic #100DaysOfCode #SoftwareDevelopment #JavaDeveloper #CodingJourney #final #finalkeyword

Day 94/100 – Consistency Journey Today’s focus: Strings in DSA + Java Multithreading Practiced string problems involving sliding window, two pointers, and pattern-based thinking. Realized how much efficiency improves when you move from brute force to optimized approaches. On the backend side, explored ExecutorService in Java — understanding how thread pools help manage multiple tasks efficiently instead of creating threads manually every time. Key takeaway: DSA builds problem-solving mindset, while backend concepts like multithreading show how things actually scale in real-world systems. Slowly connecting both worlds. Consistency > Motivation. #Day94 #100DaysOfCode #DSA #Java #BackendDevelopment #LearningInPublic

Day 36/100 – Working with ArrayList in Java 📚 Today I practiced using ArrayList in Java, a dynamic array that allows flexible storage and manipulation of data. Unlike normal arrays, ArrayList can grow and shrink dynamically, making it very useful in real-world applications. Key learnings: • Adding elements using add() • Storing multiple values dynamically • Finding size using size() • Easier and more flexible than traditional arrays Understanding collections like ArrayList is important for handling data efficiently in Java. Building strong fundamentals step by step. 🚀 #100DaysOfCode #Java #ArrayList #DataStructures #CodingJourney #LearningInPublic