Sum of Unique Elements LeetCode Challenge

🚀 Day 26/100 – LeetCode Challenge ✅ Problem Solved: Valid Perfect Square Today’s problem was about checking whether a number is a perfect square without using any built-in functions like sqrt. I solved it using Binary Search, which helped efficiently determine whether there exists an integer whose square equals the given number. 💡 Key Learning: Binary Search can be applied beyond arrays Handling large numbers requires careful use of data types Avoiding overflow is important in mathematical problems ⚡ Complexity: Time: O(log n) Space: O(1) Learning to apply fundamentals in different ways every day 🚀 #Day26 #100DaysOfCode #LeetCode #DSA #Cpp #CodingJourney #BinarySearch #ProblemSolving

🚀 Day 27/100 – LeetCode Challenge ✅ Problem Solved: Remove Duplicates from Sorted Array Today’s problem was a classic example of using the two-pointer technique. The goal was to remove duplicates from a sorted array in-place while maintaining the order of elements. I used two pointers to track unique elements and overwrite duplicates efficiently without using extra space. 💡 Key Learning: Two-pointer technique is very effective for array problems In-place operations help reduce space complexity Understanding problem constraints leads to optimal solutions ⚡ Complexity: Time: O(n) Space: O(1) Consistency is building confidence step by step 🚀 #Day27 #100DaysOfCode #LeetCode #DSA #Cpp #CodingJourney #TwoPointers #ProblemSolving

Day 29 – LeetCode Journey 🚀 Solved Two Sum II – Input Array Is Sorted using the Two Pointer technique, leveraging the sorted nature of the array for an optimal solution. 🔹 Time Complexity: O(n) 🔹 Runtime: 2 ms (Beats 96.37%) 🔹 Memory Usage: 48.58 MB This problem is a great reminder that recognizing patterns (like sorted arrays) can significantly reduce complexity and improve efficiency. Small optimizations, big impact 📈 Staying consistent and sharpening problem-solving skills every day. #LeetCode #DSA #ProblemSolving #CodingJourney #SoftwareEngineering #Consistency #Learning

🚀 Day 21/100 – LeetCode Challenge ✅ Problem Solved: Find All Lonely Numbers in the Array Today’s problem was about identifying “lonely” numbers — elements that appear only once and have no adjacent numbers present in the array. I used a hash map approach to efficiently track the frequency of each number and then checked whether its neighboring values existed or not. This helped in filtering out only the valid lonely numbers. 💡 Key Learning: Frequency counting simplifies many array problems Edge case handling (n-1 and n+1) is important Hashing provides efficient lookups in O(1) time ⚡ Complexity: Time: O(n) Space: O(n) Consistency is the real game changer — one problem a day 🚀 #Day21 #100DaysOfCode #LeetCode #DSA #Cpp #CodingJourney #ProblemSolving

Day 30 – LeetCode Journey 🚀 Solved Trapping Rain Water — a classic Hard problem that tests deep understanding of two-pointer optimization and space efficiency. Instead of brute force or extra space, applied an optimized two-pointer approach to compute trapped water in a single pass. 🔹 Time Complexity: O(n) 🔹 Runtime: 0 ms (Beats 100%) ⚡ 🔹 Memory Usage: Optimized This problem reinforced how powerful pointer techniques can be when combined with the right intuition. 30 days of consistency, learning, and growth — and just getting started 💪 #Day30 #LeetCode #DSA #ProblemSolving #CodingJourney #SoftwareEngineering #Consistency #KeepLearning

🚀 Day 18/100 – LeetCode Challenge Today’s problem: Linked List Cycle Detection Finally got hands-on with the famous Floyd’s Cycle Detection Algorithm (Tortoise & Hare) — and it was a great learning experience! 🧠 💡 Key Learnings: - Using two pointers ("slow" & "fast") can optimize both time and space - If a cycle exists, both pointers are bound to meet at some point - No extra space needed → O(1) space complexity 🔥 ⚡ Complexity: - Time: O(n) - Space: O(1) What I really liked about this problem is how a simple idea (different speeds) leads to an efficient and elegant solution. Problems like these remind me why consistency matters in DSA practice. #100DaysOfCode #LeetCode #DSA #CodingJourney #Consistency #ProblemSolving

🚀 Day 26/100 — LeetCode Challenge Today's problem: Search in Rotated Sorted Array II 🧠 Concept: Binary Search with Edge Cases 💡 Key Idea: Duplicates can make it difficult to identify the sorted half. In such cases, shrink the search space from both ends. ⚡ Time Complexity: O(log n) average, O(n) worst case 📂 Solutions Repository https://lnkd.in/gkFh2mPZ A great example of how edge cases can complicate an otherwise straightforward approach. #100DaysOfLeetCode #DSA #LeetCode #CodingChallenge #SoftwareEngineering

🚀 Day 7/100 — LeetCode Challenge Solved Search in Rotated Sorted Array II At first, it feels similar to the previous rotated array problem, but duplicates make it harder to decide which half is sorted. 💡 Key idea: 1) Normally, one half is always sorted 2) But with duplicates, we can get stuck when low == mid == high 3) In that case, we shrink the search space from both ends 4) Otherwise, identify the sorted half and proceed like binary search 👉 Small change, but big impact on logic. 🧠 Time Complexity: Average: O(log n) Worst case: O(n) (due to duplicates) 💾 Space Complexity: O(1) Learning that small edge cases can completely change how an algorithm behaves. Staying consistent. #LeetCode #DSA #100DaysOfCode #Cpp #BinarySearch #CodingJourney

Day 41 | LeetCode Learning Journal 🚀 Today I solved Problem 230: Kth Smallest Element in a BST. It’s amazing how a foundational concept like Inorder Traversal becomes such a powerful tool when applied to Binary Search Trees. Since an inorder traversal of a BST naturally visits nodes in ascending order, the problem transforms from a "search" into a "counting" exercise. It really reinforced the idea that understanding the inherent properties of a data structure is 90% of the battle. Key Takeaways from today: BST Properties: Inorder traversal = Sorted order. Keeping this in mind simplifies so many tree-based problems. Pass by Reference: Using reference variables for count and ans in recursion allows for efficient state tracking without global variables. #LeetCode #100DaysOfCode #CodingJourney #ProblemSolving #CPlusPlus #DSA #BinarySearchTree #Recursion #GrowthMindset #CodeLife

Just crossed 100 problems solved on LeetCode. Not impressive by itself—but what matters is consistency. Most of these came from sticking to fundamentals like arrays, two pointers, and basic problem patterns instead of jumping around randomly. Current focus: • Strengthening problem-solving patterns • Reducing time per problem • Moving from Easy → Medium consistently Still a long way to go. Next target: 200 with stronger Medium coverage. If you're grinding LeetCode too, focus less on quantity and more on pattern recognition—it compounds faster. #LeetCode #DSA #CodingJourney #ProblemSolving #SoftwareEngineering