Reverse Number and Find Difference

Day 77 of my DSA Journey Solved Find the Duplicate Number Problem: Given an array of size n+1 with numbers from 1 to n, find the duplicate number. 💡 Approach I used: Created a frequency array Counted occurrences of each number Returned the number that appeared more than once ⚡ Key Learnings: This approach is simple and works well for understanding the problem Time Complexity: O(n) Space Complexity: O(n) 🔥 Important Insight: This problem is more interesting than it looks — it can be solved without extra space using Floyd’s Cycle Detection (Tortoise & Hare algorithm), which is commonly expected in interviews. 📈 Takeaway: Always try to improve from a basic solution to an optimized one. #Day77 #DSA #LeetCode #Java #CodingJourney

🚀 Day 45 of #DSA ✅ Solved: Find First and Last Position of Element in Sorted Array (LeetCode 34) Today’s problem was a great application of Binary Search to find both the first and last occurrence of a target element. 💡 Key Insight: Instead of scanning linearly, we use binary search twice — once for the first position and once for the last — achieving O(log n) time complexity. ⚙️ Approach: - Apply binary search to find first occurrence - Apply binary search again to find last occurrence - Combine both results 📚 Key Learning: Small modifications in Binary Search can solve multiple variations — mastering this pattern is very important for interviews. Consistency is building strong fundamentals 💯 #Day45 #BinarySearch #LeetCode #Java #DSA #CodingJourney #ProblemSolving #100DaysOfCode #Tech

🚀 Day 41 of #DSA ✅ Solved: Daily Temperatures (LeetCode 739) Today’s problem was about finding how many days we need to wait for a warmer temperature. 💡 Key Insight: Instead of checking every future day (which is slow), we use a Monotonic Stack to efficiently track unresolved days. This reduces complexity to O(n). ⚙️ Approach: - Store indices in a stack - If current temperature is higher → resolve previous indices - Calculate days difference and update result ⏱ Complexity: - Time → O(n) - Space → O(n) 📚 Key Learning: This problem is a classic example of Next Greater Element pattern using stacks — very important for coding interviews. Consistency is the key 🔑 #Day41 #LeetCode #Java #DSA #CodingJourney #ProblemSolving #100DaysOfCode #Tech

🚀 I Created 32 Pages of Data Structures & Algorithms Notes (Java) After weeks of consistent learning, I’ve compiled a complete DSA notes collection covering: ✔️ 20 core topics (Arrays, Trees, Graphs, Dynamic Programming, etc.) ✔️ Java implementations with clear explanations ✔️ Key interview patterns (Sliding Window, Two Pointers) ✔️ Big-O complexity + quick revision cheat sheet 💡 Why I made this: • To simplify complex DSA concepts • To build strong problem-solving skills • To prepare effectively for coding interviews 📘 Download the notes here If you're preparing for placements or interviews, this might help you. 💬 Let me know your feedback! #DSA #Java #Coding #SoftwareEngineering #DataStructures #PlacementPreparation #LearnInPublic

DSA Practice Update Today I solved: #141 – Linked List Cycle Learned how to detect a cycle in a linked list using Floyd’s Cycle Detection Algorithm (fast and slow pointers). Understood how moving pointers at different speeds helps identify if a loop exists without using extra space. Key Learnings: • Fast and slow pointer technique • Detecting cycles efficiently in O(n) time • Solving problems with constant space complexity This problem strengthened my understanding of pointer-based approaches, which are commonly used in linked list interview questions. Continuing to stay consistent and improve problem-solving skills step by step. #DSA #LeetCode #CodingJourney #Java #SoftwareDevelopment #PlacementPreparation

DSA Practice Update Today I solved: #78 – Subsets Learned the backtracking approach to generate all possible subsets (power set). Understood how to explore both choices at each step: including or excluding an element, and how to use recursion with backtracking to build all combinations. Key Learnings: • Introduction to backtracking technique • Recursion with decision making (pick / not pick) • Building combinations step by step This problem helped me understand the fundamentals of backtracking, which is an important concept for many interview problems. Continuing to stay consistent and strengthen core concepts. #DSA #LeetCode #CodingJourney #Java #SoftwareDevelopment #PlacementPreparation

Solved: Count Number of Factors of N (DSA) Today I worked on a classic problem — finding the number of divisors of a number. 🔹 Started with a basic approach: O(N) 🔹 Optimized it to: O(√N) using divisor pairs 💡 Key Insight: Every divisor i has a corresponding pair N/i, which helps reduce the number of iterations significantly. Also handled the edge case of perfect squares carefully ✔️ This is a small problem, but it builds strong fundamentals for: Number Theory Competitive Programming Technical Interviews Would love feedback from the community 🙌 #DSA #Java #Coding #ProblemSolving #SoftwareEngineering #LearningInPublic

🚀 From Confusion to Clarity: Day 69 of My DSA Journey Today’s focus was on strengthening core problem-solving patterns and improving implementation clarity. 🔹 Solved and revised key problems across: HashMap, Sliding Window, Prefix Sum, and Kadane’s Algorithm Strengthened understanding of pattern recognition and when to apply them 🔹 Deep Dive: Reverse Linked List (LeetCode 206) Instead of memorizing, I focused on understanding pointer manipulation: ✔️ Learned the importance of storing the next node before breaking links ✔️ Understood how incorrect pointer updates can break the entire structure ✔️ Improved ability to debug and refine my approach step-by-step 💡 Key Insight: Writing code is not enough — understanding why it works is what builds real problem-solving skills. 📈 Progress Mindset: First attempt → Mistakes Debugging → Learning Final solution → Clarity Consistently focusing on patterns + clean implementation + explanation skills to prepare for real interview scenarios. #DSA #LeetCode #Java #ProblemSolving #CodingJourney #SoftwareEngineering #InterviewPreparation

🚀 Day 22 of My DSA Journey Today I solved an important Binary Search problem: 👉 Find First and Last Position of Element in Sorted Array 🧩 Problem Understanding Given a sorted array and a target value, we need to find the starting and ending position of the target element. If the target is not present, return [-1, -1]. 🔍 Approach I Used (Binary Search x2) Instead of linear search, I used Binary Search twice: ✔️ First Binary Search → to find the first occurrence ✔️ Second Binary Search → to find the last occurrence 💡 Trick: Even after finding the target, we don’t stop — we continue searching on left/right side to get the boundary indices. ⚡ Why this approach? Because the array is sorted → Binary Search reduces time complexity drastically. ⏱ Time Complexity: O(log n) 📦 Space Complexity: O(1) 🔥 Key Learning Binary Search is not just for finding elements — it can also be used to find boundaries, ranges, and conditions. Consistency is the real game changer 💪 One problem at a time! #DSA #BinarySearch #LeetCode #Java #ProblemSolving #100DaysOfCode #CodingJourney #LearningInPublic

🚀 Improving DSA one step at a time! Today I solved LeetCode 1446 – Consecutive Characters 🧠 🔍 Problem Insight: Find the longest substring where all characters are the same. 💡 Approach: Traverse the string and keep counting consecutive characters while tracking the maximum. ⚡ Time Complexity: O(n) ⚡ Space Complexity: O(1) 🎥 Full explanation: 👉https://lnkd.in/gbqbVV5Q 🔥 I’m posting daily LeetCode solutions with simple explanations. 👉 Follow me for DSA 👉 Subscribe for full tutorials 💬 Comment “DSA” if you're preparing for interviews! #LeetCode #DSA #Java #Coding #Programming #InterviewPrep #Developers