Mastering Java with LeetCode Linked List Problem 2130

Day 94 - LeetCode Journey Solved LeetCode 35: Search Insert Position in Java ✅ Classic Binary Search problem that tests your fundamentals. Instead of just finding the element, the twist is to return the correct insert position if it’s not present. The key idea is simple: keep narrowing the search space and finally return low, which represents the right position. Clean logic, high impact 💡 Key takeaways: • Strong grip on Binary Search fundamentals • Understanding search space boundaries • Returning correct insertion index • Writing efficient O(log n) solutions ✅ All test cases passed ⚡ O(log n) time and O(1) space Mastering basics like Binary Search is what builds real problem-solving strength 🔥 #LeetCode #DSA #Java #BinarySearch #ProblemSolving #CodingJourney #InterviewPrep #Consistency #100DaysOfCode

Today I worked on a problem that involved finding the maximum count of positive and negative numbers in a sorted array. Key idea: Used Binary Search to efficiently find: The first positive number The first non-negative number From this, we can calculate: Count of positive numbers Count of negative numbers Why Binary Search? Because the array is sorted, it helps reduce time complexity to O(log n) instead of scanning the entire array. What I learned: How to apply binary search beyond just finding elements How to think in terms of boundaries (first occurrence logic) Writing clean and optimized Java code 📌 Problem-solving is not just about coding, it's about thinking efficiently. Looking forward to learning more and improving every day! #Java #DSA #BinarySearch #CodingJourney #ProblemSolving #LearningEveryday

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

💻 Today I practiced a simple but important Java problem reading input until End of File (EOF). The task is to take input line by line and print each line along with its line number. Since we don’t know how many lines the user will enter, we use hasNextLine() inside a loop to keep reading until the input ends. I used a counter starting from 1, read each line using nextLine(), and printed it with the line number. Then I incremented the counter for the next line. This problem looks basic, but it’s very useful in coding platforms like HackerRank where input is not fixed. It also helps in understanding how input streams work in Java. Small problems like this really help in building strong fundamentals. #Java #CodingPractice #InterviewPreparation

🚀 Day 1 of mastering Java Exception Handling Instead of passively reading, I decided to actively practice like an interview. Here’s what I covered today: ✅ Checked vs Unchecked Exceptions → Compile-time vs Runtime → Why some MUST be handled ✅ try-catch-finally behavior → “finally always executes?” → Not always (System.exit, JVM crash) ✅ throw vs throws → One throws, one declares — simple but often confused ✅ Multiple catch blocks → Ordering matters (specific → general) ✅ Custom Exceptions → Creating meaningful errors instead of generic ones 💡 Biggest realization: Knowing definitions is easy. Explaining them clearly under pressure is the real skill. 🎯 Plan: → Day 2: Deeper concepts + edge cases → Day 3: Tricky output questions (real interview level) #Java #Coding #InterviewPreparation #LearningInPublic #100DaysOfCode

Solved Simple Array Sum using LinkedList in Java 8 💻📊 Today I worked on the Simple Array Sum problem and implemented it using LinkedList in Java 8. 💡 What I learned: How to convert a List into a LinkedList Traversing elements efficiently using loops Using Java 8 Streams for cleaner and shorter code ⚙️ Approach: Converted input list into a LinkedList Iterated through elements and calculated sum Also explored stream().mapToInt().sum() for optimized solution 📌 Key Takeaway: Even simple problems help strengthen core concepts like data structures and improve coding efficiency. ⚡ Time Complexity: O(n) ⚡ Space Complexity: O(n) 👨💻 Consistent practice is helping me improve my problem-solving skills step by step. #Java #Java8 #LinkedList #Coding #ProblemSolving

Solved "Drawing Book" Problem Using Java 📖💻 | HackerRank Challenge Solved the Drawing Book (Page Count) problem from HackerRank using Java! This problem is a great example of optimization and logical thinking, where instead of simulating page turns, we calculate the minimum turns mathematically. 🔍 Key Concepts Used: Mathematical Optimization Integer Division Problem-Solving Approach 📌 Logic Summary: Count page turns from the front → p / 2 Count page turns from the back → (n / 2) - (p / 2) Return the minimum of both values 💡 This approach ensures O(1) time complexity, making it efficient and clean. Always improving problem-solving skills one challenge at a time 🚀 #Java #HackerRank #CodingChallenge #ProblemSolving #DSA

🚀 Mastering Java Through LeetCode 🧠 Day 29 Today I solved an interesting Medium-level problem that strengthens understanding of Linked List manipulation & pointer handling 💡 📌 LeetCode Problem Solved: Q.328. Odd Even Linked List 🔍 Problem Summary: Given a singly linked list, group all nodes at odd indices together followed by nodes at even indices. 👉 Maintain the relative order of both groups 👉 Solve in O(n) time and O(1) space 💡 Approach: Use two pointers: odd and even Separate odd-indexed and even-indexed nodes Connect the end of odd list to the head of even list ✅ Key Takeaways: In-place linked list manipulation is powerful 🔥 Pointer movement is crucial in optimizing space Great problem to strengthen interview concepts 📈 Consistency is the key — one problem a day! #LeetCode #Java #DataStructures #LinkedList #CodingJourney #SoftwareEngineer #CodingInterview #100DaysOfCode #PlacementPreparation #TechCareers #Developers #ProblemSolving

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

🚀 Mastering Java Through LeetCode 🧠 Day 25 Today I solved another interesting problem that involves Stack + String manipulation, which is very important for interviews. 📌 LeetCode Problem Solved Today: Q.394 – Decode String 💡 Problem Statement: Given an encoded string, decode it using the rule: k[encoded_string] → repeat the string k times Example: "3[a2[c]]" → "accaccacc" Approach: I used a Stack-based approach to handle nested patterns efficiently: Use one stack for numbers (repeat count) Use another stack for strings Traverse the string character by character Key Logic: Handle multi-digit numbers using: k = k * 10 + digit Store previous state using stacks Build final string using StringBuilder Supports nested decoding like "3[a2[c]]" Time Complexity: O(n) Space Complexity: O(n) What I Learned: How to use stacks for nested structures Importance of handling multi-digit numbers Clean string building using StringBuilder #Java #DSA #LeetCode #CodingInterview #SoftwareEngineer #Stack #DataStructures #ProblemSolving #100DaysOfCode #Programming #Developers #TechCareers #CodingJourney #LearnToCode #JavaDeveloper #InterviewPreparation