100 Days LeetCode Challenge Completed: Consistency and Discipline Key to Learning

Day 55 of 100 Days of LeetCode 💻 Today I solved Longest Consecutive Sequence — and honestly, this one taught me more about coding discipline than algorithms. At first, my approach was correct: Used HashSet for O(1) lookup Applied the “start of sequence” logic But I still got TLE. The reason? A tiny mistake: if(!set.contains(num-1)); That single ; made my condition useless and turned my O(n) solution into O(n²). 💡 Lesson learned: Don’t just think your logic is right → verify what your code actually does Small syntax mistakes can completely break optimal solutions Debugging is just as important as problem-solving Finally fixed it and got Accepted ✅ Slowly improving not just in DSA, but in writing cleaner and more careful code. #100DaysOfLeetCode #DSA #Java #CodingJourney #Learning

Day-3 of My Coding Journey Today I worked on the LeetCode problem: 👉 Find Numbers with Even Number of Digits What I learned: How to count digits in a number using String.valueOf(num).length() How to check if a number has even digits using % 2 == 0 ❌ My Mistake: I wrote: String.value(num).length % 2 == 0 ✔ Issues: Used value() instead of valueOf() Forgot () in length ✅ Fix: String.valueOf(num).length() % 2 == 0 After correcting this, my solution got Accepted! ✨ Takeaway: Small syntax mistakes can cause errors, but fixing them improves attention to detail and strengthens fundamentals. #Day3 #LeetCode #Java #CodingJourney #Learning 10000 Coders

🚀 Day 6 of LeetCode Problem Solving Solved today’s problem — LeetCode #1480: Running Sum of 1d Array 💻🔥 ✅ Approach: Prefix Sum (Running Sum) ⚡ Time Complexity: O(n) 📊 Space Complexity: O(n) The task was to compute the running sum of an array where each element represents the sum of all previous elements including itself. 👉 Example: Input: [1,2,3,4] Output: [1,3,6,10] 💡 Key Idea: Keep adding elements as you traverse the array and store the cumulative sum. 👉 Core Logic: Initialize sum = 0 Traverse array Add current element → sum += nums[i] Store in result array 💡 Key Learning: Simple problems help build strong fundamentals — mastering basics like prefix sum is very important for advanced problems. Grateful to my mentor Pulkit Aggarwal — your guidance is helping me strengthen my fundamentals every day 🙌 Consistency is the key — small steps lead to big results 🚀 #Day6 #LeetCode #DSA #Java #CodingJourney #ProblemSolving #100DaysOfCode

At first, the Rotate Image problem looked tricky. Rotating a matrix in-place isn’t something that feels obvious right away. But after thinking about it, I realized it’s not about rotation directly, it’s about transforming the matrix step by step. By first flipping it across the diagonal (transpose) and then reversing each row, the rotation happens naturally. Moments like this remind me that in coding, the right approach often matters more than the problem itself. Learning to break problems down is the real skill. RAVI KUMAR Coding Blocks Sunstone #Coding #DSA #Java #ProblemSolving #GrowthMindset #Learning

🚀 Day 10 of #100DaysOfDSA – Solved LeetCode 344: Reverse String Today’s problem was simple yet powerful — Reverse a String (in-place) 💡 🔹 Problem: Given a character array, reverse it without using extra space. 🔹 Approach: Used the Two Pointer Technique: 👉 Start one pointer from the beginning 👉 Another from the end 👉 Swap characters and move inward 🔹 Key Learning: In-place operations improve space efficiency Two-pointer approach is a must-know pattern for interviews 🔹 Time Complexity: O(n) 🔹 Space Complexity: O(1) 💻 Code Insight: Swapping elements until both pointers meet does the job efficiently! ✨ Small problems like this build strong fundamentals for bigger challenges. #DSA #Java #Coding #LeetCode #Programming #SoftwareEngineering #InterviewPrep #100DaysOfCode

Bridging the Gap Between Learning & Doing 🚀 From my experience, theory alone isn’t enough—real growth comes from building, breaking, and solving. Crio helped me sharpen my skills through intense hands-on practice, working on real-world scenarios, and strengthening my Java fundamentals with new logic-building approaches. It’s not just learning—it’s continuous skill refinement. If you’re serious about leveling up with practical exposure, this is worth exploring: https://lnkd.in/gy4S3rzp #CrioDo #CareerGrowth #LearnByDoing #Java #HandsOnLearning #SkillBuilding

Day 60 of My 90-Day Coding Challenge Today I worked on a classic recursion + backtracking problem — and it really tested how well I understand breaking problems into smaller decisions. At first, it feels messy: multiple partitions, multiple choices, and many possible paths. But once you start thinking in terms of: -“Try every possible cut and validate it” the structure becomes clear. Key learning: • Recursion is about exploring all paths, not rushing to the answer • Validity checks (like palindrome here) are what control the tree • Clean backtracking (add → recurse → remove) is everything One thing that really helped today: Even if you don’t know where to start, just begin drawing the recursion tree. As you expand it step by step, the logic starts revealing itself — what choices to make, when to stop, and how to backtrack. What stood out today: Clarity in recursion doesn’t come from memorizing patterns — it comes from visualizing the process. Still improving. #90DaysOfCode #DSA #Java #Recursion #Backtracking #LeetCode #ProblemSolving

🎉 Day 8 of My 100-Day Programming Challenge! 🚀 Today, I solved the “Sqrt(x)” problem on LeetCode. The task is to compute the square root of a non-negative integer and return the result rounded down to the nearest integer, without using built-in functions like pow() or sqrt(). 🧩 🔍 Approach: I used the Binary Search technique to efficiently find the square root. ⚙️ Steps: • Define the search space from 1 to x. • Calculate the middle value (mid). • Check if mid * mid is equal to x. • If less than x, move right and store the potential answer. • If greater than x, move left. • Continue until the search space is exhausted. 💡 Key Insights: ✔ Binary Search reduces time complexity significantly. ✔ Avoids overflow using mid <= x / mid instead of mid * mid. ✔ Efficient way to compute roots without built-in functions. 🧠 Complexity: • Time Complexity: O(log n) • Space Complexity: O(1) Another great problem to strengthen Binary Search fundamentals and mathematical problem-solving skills. On to the next challenge! 💻🔥 #100DaysOfCode #Java #LeetCode #DSA #BinarySearch #Programming #CodingChallenge

Day 5 / 100 Days of Coding : Solved: Best Time to Buy and Sell Stock Today’s problem looked simple but taught a powerful concept — tracking minimums and maximizing profit in a single pass. Key Learning: Instead of checking all pairs (which is slow), we maintain: Minimum price so far Maximum profit so far This reduces complexity from O(n²) → O(n) Consistency is the real game. Showing up every day matters more than perfection. #100DaysOfCode #DSA #LeetCode #Java #CodingJourney #ProblemSolving #GreedyAlgorithm

🚀 Day 8 of LeetCode Problem Solving Solved today’s problem — LeetCode #66: Plus One 💻🔥 ✅ Approach: Digit Manipulation ⚡ Time Complexity: O(n) 📊 Space Complexity: O(1) (excluding output) The problem was about incrementing a large integer represented as an array of digits. 👉 Instead of converting it into a number, I handled it digit by digit from the end — just like how we do addition manually. 💡 Key Idea: Start from the last digit and handle carry: If digit < 9 → simply increment and return If digit == 9 → make it 0 and carry forward 👉 Edge Case: If all digits are 9 (like [9,9,9]), we need a new array → [1,0,0,0] 💡 Key Learning: Understanding how basic operations work internally (like addition) helps in solving array-based problems efficiently. Grateful to my mentor Pulkit Aggarwal — your guidance is helping me strengthen my fundamentals every day 🙌 Consistency is the key — showing up daily 🚀 #Day8 #LeetCode #DSA #Java #CodingJourney #ProblemSolving #100DaysOfCode