Practicing Java: Calculating Character Frequency with HashMap

Today, I explored some interesting LeetCode problems to strengthen my Java and DSA fundamentals. Here’s a quick breakdown of what I solved 👇 🔹 Problem 1: Toeplitz Matrix 🧩 Question: Check whether all diagonals from top-left to bottom-right contain the same elements. 🧠 Approach: Traverse the matrix and compare each element with its bottom-right diagonal neighbor. If any mismatch occurs, return false; otherwise, true. This ensures every diagonal maintains uniformity. 📊 Complexity: Time: O(m × n) Space: O(1) 💡 Key Learning: Strengthened understanding of 2D array traversal and pattern validation. 🔹 Problem 2: Largest Number At Least Twice of Others 🧩 Question: Find the index of the largest element if it’s at least twice as large as every other element; otherwise, return -1. 🧠 Approach: Scan the array once to find the largest and second-largest elements. Check if the largest element is ≥ 2 × (second-largest). If true, return its index; else, return -1. 📊 Complexity: Time: O(n) Space: O(1) 💡 Key Learning: Practiced efficient single-pass array traversal and comparison logic. 🔹 Problem 3: Shortest Completing Word 🧩 Question: Given a license plate string and a list of words, find the shortest word that contains all the letters (and their frequencies) from the license plate. 🧠 Approach: Clean the license plate (keep only letters, make lowercase). Count frequency of each letter. For each word, check if it fulfills the required frequency. Track and return the shortest valid word. 📊 Complexity: Time: O(k × n), where k = number of words and n = average word length Space: O(1) 💡 Key Learning: Improved string manipulation, frequency mapping, and logical optimization. 🔥 Overall Takeaway: Practicing diverse problems like these boosts my problem-solving mindset, enhances Java coding efficiency, and builds confidence in tackling real-world algorithmic challenges 💪 Profile link ->https://lnkd.in/gFH_4R9a #Java #LeetCode #ProblemSolving #DSA #CodingPractice #LearningJourney #Developer #TechSkills #CodingInJava

Today marks Day 26 of my Java learning journey — Today’s focus was on mastering the concept of merging two sorted arrays using the two-pointer approach — a simple yet incredibly powerful logic that forms the foundation for several advanced algorithms, including Merge Sort. When I started, I had two sorted arrays of different lengths. The goal was to combine them into one single sorted array without using any built-in sorting functions. By using two pointers, each pointing to the start of both arrays, I compared elements one by one and picked the smaller value first. This ensured that every insertion maintained the overall sorted order. What fascinated me most was how this method works in linear time O(n + m) — far more efficient than merging and sorting the entire array again. I also explored an in-place variant, where merging happens within one array itself, starting from the end. This saves extra space and demonstrates a more optimized approach, which is widely used in real-world systems such as database merge operations and sorting algorithms. Through this problem, I learned that even a seemingly small change in how we traverse arrays can drastically improve efficiency. The two-pointer pattern not only simplifies logic but also trains the mind to think in terms of data relationships and flow rather than just loops and conditions. Every day, I’m realizing that programming is more about strategic thinking than just syntax — and today’s exercise was a perfect example of that. 💡 #Java #Day26 #Programming #LearningJourney #ProblemSolving #Algorithms #DataStructures #TwoPointers #MergeSort #LogicBuilding #SoftwareDevelopment #Coding #Efficiency

🚀 #Day19 of My Coding Journey: Mastering String Handling in Java! 📢 Strings are the backbone of data in programming, and today I dove deep into String Handling in Java. It's been incredibly valuable to understand the mechanics of manipulating data, from simple text to complex messages. 📝 Here's what I learned and practiced: 🥇Comparison Methods: Explored equals(), equalsIgnoreCase(), and compareTo() to compare strings directly and by ignoring case. 🥈Case Conversion: Used toUpperCase() and toLowerCase() to standardize text formats. ♟️Length & Character Operations: Got hands-on with length() to find the size and charAt() to access specific characters. ⏳Search Operations: Practiced using indexOf() and lastIndexOf() to pinpoint the location of characters or words. 🧩Start & End Check: Learned to use startsWith() and endsWith() for specific text verification. 🎯Modification & Cleanup: Utilized replace(), trim(), split(), and concat() for cleaning, modifying, and combining strings. 📌A key takeaway was truly understanding why strings in Java are immutable—once created, their value can't be changed. This solidifies my understanding of how Java manages memory and data integrity. 🪄This is a crucial step toward building strong fundamentals and processing real-world text data efficiently! A special thanks to my mentor Anand Kumar Buddarapu and Codegnan for their continuous guidance! Saketh Kallepu &Uppugundla Sairam #Java #StringHandling #Programming #CodingJourney #Day19 #TechSkills

🚀 Week 5 of My Java Learning Journey! This week, I explored String Concepts in Java — one of the most powerful and commonly used data types! 🔤 It was exciting to understand how Strings work internally and how many different operations can be performed using built-in methods. 💻 🧩 Key Learnings: What is String & how it is stored in memory String vs StringBuilder vs StringBuffer String methods (length, charAt, substring, indexOf, equals, compareTo, replace, trim, split, etc.) Immutable vs Mutable strings String concatenation & performance 💻 Practice Programs: Reverse a string Count vowels & consonants Check palindrome string Compare two strings Word / character frequency Splitting sentences into words 📝 Extra Skill: Explored performance difference between String vs StringBuilder using loop concatenation 🔗 Check out my Week 5 GitHub repo: https://lnkd.in/giiR_G86 Excited for Week 6, where I’ll dive into Object-Oriented Programming (OOPs) Concepts — taking Java to the next level! 🚀 #Java #Programming #CodingJourney #Git #GitHub #100DaysOfCode #Learning #Backend #Strings

🚀 Day 27 of 100 Days of LeetCode 📘 Problem: Generate Parentheses 💻 Language: Java ✅ Status: Accepted — Runtime: ⚡ 0 ms (Beats 100%) Today’s challenge focused on backtracking, one of the most elegant and powerful problem-solving techniques in DSA. The task was to generate all possible valid combinations of parentheses — a perfect test of recursion and logical constraints 🧩 ✨ Key Learnings: Backtracking is about exploring all possibilities, then undoing choices when needed 🔄 Understanding base cases clearly makes recursion much easier Clean recursive structures lead to elegant and efficient solutions This problem reinforced one important principle — 🧠 “Sometimes, going back is the only way to move forward — both in code and in life.” #Day27 #100DaysOfCode #LeetCode #Java #Backtracking #Recursion #ProblemSolving #CodingJourney #DSA #SoftwareDevelopment #KeepLearning #CodeEveryday

📚 Revise – : #Arrays in #Java 💻 Kicking off my Revise series! Today, I’m sharing a detailed PDF guide on Arrays covering: Introduction & real-life examples 🏢🥚 1D arrays: declaration, initialization, accessing elements Loops for array iterations: for, for-each, while, do-while, reverse, nested 🔄 Array properties & methods: length, #Arrays.sort(), #Arrays.copyOf(), #binarySearch(), and more. Entry, mid, and senior-level interview theoretical questions Coding challenges to boost your problem-solving skills 💡 Note: I’ll be sharing answers to all questions tomorrow. Perfect for learners and developers looking to strengthen their Java foundation – the backbone of #data_structures! #DSA, #Consistency #Algorithms #Logic #Coding #Programming

💻 Mastering Java Through Practice! ☕ Over the past few days, I’ve been diving deep into Java fundamentals by solving 30+ hands-on coding problems — from string manipulation and arrays to matrix operations and logic-based challenges. Each program helped me strengthen my problem-solving mindset and understand how real-world logic translates into code. Here are some key takeaways from this practice: ✅ Understanding how loops, conditions, and string methods work behind the scenes ✅ Writing clean and reusable Java code ✅ Learning the importance of edge cases and user input handling ✅ Gaining confidence with interview-level programs like: 🔁 Reversing strings and sentences 🔢 Counting vowels, digits, and special characters 🧮 Sorting arrays and finding 2nd highest numbers 🔤 Checking anagrams and palindromes 🔄 Rotating matrices clockwise and anticlockwise ✨ Every small project like this builds the foundation for writing efficient and optimized code. 📘 Next goal: Apply these concepts to build Java-based applications (like quizzes, utilities, or small tools). 👉 If you’re also learning Java, start with these kinds of mini-programs — they’re simple but powerful in shaping your logic. #Java #Coding #Programming #DeveloperJourney #LearningByDoing #ProblemSolving #SoftwareEngineering #100DaysOfCode

🚀Day 53 #180daysofconsistency Deep Dive into Exception Handling, Java & Python ⚙️ Before exceptions, developers used return codes, global flags, and manual clean-ups, which often led to messy code, missed errors, and resource leaks. In this part, I explored how exception handling revolutionized modern programming by making our code: ✅ Cleaner — separates normal logic from error logic ✅ Safer — ensures automatic clean-up using try-with-resources (Java) and with (Python) ✅ Smarter — propagates context to where recovery actually makes sense 🔹 Java Focus: try, catch, finally, throws, and best practices like multi-catch & specific exception handling. 🔹 Python Focus: try, except, else, finally, raise, and Pythonic EAFP (“Easier to Ask Forgiveness than Permission”). 🔹 Key Lesson: Catch only what you can fix; let it crash safely when you can’t. 📘 Full guide PDF: Exception Handling in Java & Python , A Deep, Engineer-Friendly Guide Thank you to algorithms365 and Under the Guidance of Mahesh Arali Sir 🙏🏻 🧑💻 #Java #Python #DSA #ExceptionHandling #CleanCode #SoftwareEngineering #LearningJourney

🌟 Day 22 of My Java Learning Series 🌟 Today’s focus: Inheritance — a core pillar of OOP that unlocks code reusability, modularity, and scalability. 🔍 Covered Concepts: Types: Single, Multilevel, Hierarchical Advantages: Less duplication, better maintainability Rules: No inheritance of private members or constructors this() vs super() — constructor chaining made clear Method types: Inherited, Overridden, Specialized Access Specifiers: public, protected, default, private 💡 Manual implementation + debugging = clarity unlocked! Each concept felt like a puzzle piece falling into place. Let’s connect if you’re learning Java or prepping for interviews — I’d love to grow together! #JavaLearning #OOPsConcepts #InheritanceInJava #thisVsSuper #AccessSpecifiers #CodeNewbie #WomenInTech #100DaysOfCode #TapAcademy #InterviewPrep #SowmyaLearnsJava #JavaDeveloper #LearningNeverStops #TechJourney TAP Academy

🔥 Day 83 of #100DaysDSAChallenge 📌 Topic: String — Most Common Word ✅ Problem Solved on #LeetCode: 819. Most Common Word (🟢 Easy) 💡 Key Learnings: • Practiced text normalization by removing punctuation and handling case sensitivity. • Strengthened understanding of frequency counting using HashMap and HashSet. • Improved efficiency by eliminating nested loops and using optimized data structures. • Enhanced clarity in writing clean, readable, and optimized Java code. 🚀 Consistency Builds Clarity: Each problem enhances your logical thinking and improves your code precision. Keep learning and growing — one problem at a time 💪 🏷️ #Day83 #100DaysChallenge #100DaysDSAChallenge #LeetCode #Java #CodingChallenge #ProblemSolving #DataStructures #Algorithms #Strings #Programming #LearningJourney #10kCoders #10000Coders #Consistency #LogicBuilding