Java DSA: Valid Palindrome Solution with Two Pointers

Sudoku Solver: Built a Java program that solves Sudoku puzzles automatically using backtracking. The program takes an unsolved grid and fills in the correct numbers. Concepts used: Recursion, Backtracking, Arrays #Java #Coding #Learning #DSA

🚀 Day 40 / 180 – DSA with Java 🚀 📘 Topic Covered: Binary Exponentiation (Fast Power) 🧩 Problem Solved: Pow(x, n) Problem: Implement a function to calculate x raised to the power n, handling both positive and negative values of n. Approach: Used Binary Exponentiation to reduce time complexity. Repeatedly squared the base and halved the exponent, multiplying the result only when needed. Also handled negative powers by taking the reciprocal. Key Learning: ✔️ Optimizing from O(n) to O(log n) ✔️ Understanding divide-and-conquer in exponentiation ✔️ Handling edge cases like negative powers If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #ProblemSolving #Consistency 

🚀 Day 37 / 180 – DSA with Java 🚀 📘 Topic Covered: Arrays & Two-Pointer Technique 🧩 Problem Solved: Squares of a Sorted Array Problem: Given a sorted array of integers (including negatives), return a new array of the squares of each number, also sorted in non-decreasing order. Approach: Used a two-pointer approach from both ends of the array. Compared squares of elements and filled the result array from the end to maintain sorted order efficiently. Key Learning: ✔️ Handling negative values in sorted arrays ✔️ Using two-pointer technique for optimal solutions ✔️ Avoiding extra sorting to achieve O(n) time complexity If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Arrays #ProblemSolving #Consistency 

Day 65 of #100DaysOfLeetCode 💻✅ Solved “Majority Frequency Group” problem in Java. Approach: • Created a frequency array of size 26 for all characters • Counted occurrences of each character in the string • For each unique frequency, counted how many characters share that frequency • Selected the frequency with the highest group size • In case of tie, chose the higher frequency • Built the result string with characters having the selected frequency Performance: ✓ Runtime: 5 ms (Beats 57.84% submissions) ✓ Memory: 44.51 MB (Beats 72.88% submissions) Key Learning: ✓ Practiced frequency grouping techniques ✓ Learned how to handle tie-breaking conditions ✓ Strengthened logic building with nested loops and conditions Learning one problem every single day 🚀 #Java #LeetCode #DSA #Strings #Hashing #ProblemSolving #CodingJourney #100DaysOfCode

🚀 100 Days Java + DSA Challenge | Day 2 Today’s focus was on strengthening my programming fundamentals by covering: 🔹 Operators in Java (Arithmetic, Relational, Logical, Assignment) 🔹 Conditional Statements (if, if-else, nested if, switch) Understanding how operators work and how decisions are made in code is essential for building strong logic. These concepts are the backbone of problem-solving in Data Structures and Algorithms. 💡 Practiced writing multiple programs using conditions and improved my logical thinking step by step. Consistency is the key — small progress every day leads to big results. #100DaysOfCode #Java #DSA #LearningJourney #Coding #SoftwareDevelopment

🚀 Day 41 / 180 – DSA with Java 🚀 📘 Topic Covered: Matrices & Marking Technique 🧩 Problem Solved: Set Matrix Zeroes Problem: Given a matrix, if an element is 0, set its entire row and column to 0. Approach: Used two auxiliary arrays to mark rows and columns that contain zeroes. In a second pass, updated the matrix by setting elements to zero based on the marked rows and columns. Key Learning: ✔️ Handling matrix-based transformations ✔️ Using extra space for clarity and simplicity ✔️ Breaking the problem into marking and updating phases If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Arrays #ProblemSolving #Consistency

🚀 Day 38 / 180 – DSA with Java 🚀 📘 Topic Covered: Strings & Two-Pointer Technique 🧩 Problem Solved: Is Subsequence Problem: Given two strings s and t, check whether s is a subsequence of t. Approach: Used two pointers to traverse both strings. Moved the pointer in s only when characters matched, and always moved the pointer in t, ensuring order is maintained. Key Learning: ✔️ Applying two-pointer technique on strings ✔️ Understanding subsequence vs substring ✔️ Writing clean and efficient O(n) solutions If you’re also preparing for DSA, let’s connect and learn together 🤝 #DSA #Java #180DaysOfCode #LearningInPublic #Strings #ProblemSolving #Consistency

🚀 Today is Day 103 of Learning DSA with JAVA Today I solved LeetCode 746 – Min Cost Climbing Stairs 💡 👉 Problem Understanding: We need to find the minimum cost to reach the top of the stairs. At each step, we can move either 1 step or 2 steps. 👉 My Approach (Recursion + DP): First, I used recursion and called the function from both starting points: ➡️ recur(0) and recur(1) Then I took the minimum of both results. 👉 Inside Recursive Function: Base Case: If i >= n, return 0 DP Check: If value already exists in dp[i], return it Two Choices:cost[i] + recur(i+1) → move 1 step cost[i] + recur(i+2) → move 2 steps Store the result in dp[i] and return minimum 👉 Optimization: I used memoization (DP array) to avoid recalculating values This helped reduce time complexity to O(N) 💭 What I learned today: How recursion works with multiple choices How DP helps optimize recursive solutions Importance of storing computed results 🔥 Staying consistent and improving every day! #DSA #Java #LeetCode #DynamicProgramming #Recursion #CodingJourney #100DaysOfCode

Today I implemented Array Reversal in Java using the Two-Pointer Technique! 🔄 Logic: ∙ Set left = 0 and right = arr.length - 1 ∙ Swap elements at both ends ∙ Move pointers inward until they meet ✅ Input: {1, 2, 3, 4, 5} ✅ Output: 5 4 3 2 1 💡 Why Two-Pointer? Instead of using extra space, we swap in-place — making it O(n) time and O(1) space! No extra array needed. Just two pointers doing the work. 💪 Every small concept I practice brings me one step closer to DSA mastery. Keep building. Keep learning. 🙌 #100daysofcode #dsa #java #program #array #problem #leetcode #javadeveloper #learning

Understanding the difference between shallow copy and deep copy in Java really changed how I think about object handling and memory. A shallow copy duplicates the reference — meaning changes in one object can unexpectedly affect another. On the other hand, a deep copy creates an entirely independent object with its own memory allocation. This concept might seem small at first, but it becomes critical when working with complex data structures, real-world applications, and avoiding unintended side effects. Key takeaway: Always be clear whether you're copying data or just references. #Java #Programming #Learning #DSA #SoftwareDevelopment