Valid Sudoku in 36 lines with hash sets and C++

✨Day 67 LeetCode: Letter Combinations of a Phone Number (17) Approach: Used backtracking to generate all possible letter combinations mapped from digits, following the classic phone keypad pattern. ✨ Learned how recursion and backtracking can explore all possible paths efficiently — a great exercise in mapping and combinatorial logic! 📈 Improved understanding of recursion, string building, and backtracking patterns in C++. #LeetCode #100DaysOfCode #DSA #Backtracking #Strings #ProblemSolving #CodingJourney #CodeEveryday

🌿Day 73 LeetCode: Next Greater Element I (496) Approach: Used a stack to find the next greater element for each number in nums2 and stored results in a hash map for quick lookup in nums1. ✨ Learned how to use monotonic stacks for next-greater problems — a smart way to reduce time complexity and strengthen logic! 📈 Improved understanding of stacks, hash maps, and element mapping techniques in C++. #LeetCode #100DaysOfCode #DSA #Stack #HashMap #Arrays #ProblemSolving #CodingJourney #CodeEveryday

💫Day 72 LeetCode: Linked List Cycle (141) Approach: Used an unordered_set to store visited nodes while traversing the list. If a node is already present in the set, a cycle exists. ✨ Learned how hashing helps in detecting cycles efficiently without modifying the linked list — a clean and intuitive solution! 📈 Improved understanding of hash-based detection, pointer traversal, and cycle identification in C++. #LeetCode #100DaysOfCode #DSA #LinkedList #Hashing #ProblemSolving #CodingJourney #CodeEveryday

🔗 Day 63 of #100DaysOfCode 🔗 🔹 Problem: Valid Parentheses – LeetCode ✨ Approach: Implemented a stack-based validation to ensure every opening bracket has a matching closing one in correct order. Each character is checked systematically — pushing opens and popping closes — making it both clean and efficient! ⚡ 📊 Complexity Analysis: Time Complexity: O(n) — single traversal of the string Space Complexity: O(n) — stack usage for unmatched brackets ✅ Runtime: 2 ms (Beats 97.47%) ✅ Memory: 41.96 MB 🔑 Key Insight: Stacks are the unsung heroes of structured logic — from parentheses validation to syntax parsing, they keep the balance just right. 🧠 #LeetCode #100DaysOfCode #ProblemSolving #DSA #Stack #AlgorithmDesign #CodeJourney #ProgrammingChallenge #LogicBuilding #Efficiency #CodingDaily

🌻Day 56 LeetCode: Number of Ways to Split Array (2270) Approach: Calculated prefix sums to efficiently determine valid split points where the left sum is greater than or equal to the right sum. ✨ Learned how prefix sums simplify cumulative comparison problems and help avoid repeated summations — boosting both logic and efficiency! 📈 Improved understanding of prefix arrays, cumulative sums, and linear-time array traversal in C++. #LeetCode #100DaysOfCode #DSA #Arrays #PrefixSum #ProblemSolving #CodingJourney #CodeEveryday

🔢 “Today was all about turning strings into numbers — one recursive call at a time.” 🚀 Day 54/150 – DSA Challenge ✅ Problem solved: String to Integer (atoi) – LeetCode 8 (Recursion Approach) Converting a string to an integer sounds simple… until you start handling edge cases. Steps I followed: 1. Skip leading spaces. 2. Check for sign (+ / -). 3. Parse digits recursively. 4. Handle overflow by bounding between INT_MIN and INT_MAX. The recursion gave it a clean logical flow — digit by digit, call by call. ⏳ Time: O(n) 📦 Space: O(n) (recursion stack) 💡 “Recursion isn’t just looping — it’s trusting the next call to finish what you started.” 🔥 From text to integers, one call at a time. #Day54 #DSA #150DaysChallenge #LeetCode #StriverSheet #Recursion #ProblemSolving #CodingJourney #Atoi

Day 50 of #100DaysOfCode – Roman Numeral Converter in C 🏛️🔢 Today I built a classic Roman numeral converter using arrays and loops in C! 💻✨ The program takes an integer (1–3999) and maps it to its Roman numeral equivalent using a greedy algorithm. I loved how clean and logical the approach felt—matching values from largest to smallest and subtracting as we go. Also added input validation to keep it robust. Seeing "3999" turn into "MMMCMXCIX" was oddly satisfying 😄 📌 Concepts practiced: Arrays of integers and strings Looping with conditions Input validation Greedy logic for numeral mapping 🧠 Feeling more confident with string handling and formatting. Next up: maybe a Roman-to-Integer reverse converter? #Day50 #100DaysOfCode #CProgramming #CodeChallenge #LearnByDoing #CodingJourney #DevLog #CodeNewbie

Shared Libraries in C++: Spent the day diving deep into how shared libraries (.so files) actually work behind the scenes, from compilation and linking to setting up the LD_LIBRARY_PATH and running executables that depend on them. The following are some important points: 1. How to compile object files (.o) using -fPIC for position-independent code 2. Creating a shared library with g++ -shared 3. Linking the shared library with the main program 4. Using LD_LIBRARY_PATH to help the loader find .so files at runtime 5. Debugging common errors like “cannot open shared object file: No such file or directory” It was quite interesting to see how dynamic linking actually reduces redundancy and helps modularize large C++ projects efficiently. The following snapshot covers all the commands.

🚀 Day 112 of #LeetCode Challenge! Problem: Diameter of Binary Tree 💡 My Approach: The diameter of a binary tree is the longest path between any two nodes (may or may not pass through the root). The trick is to calculate the height of each subtree while keeping track of the maximum left + right path encountered. Use a helper function height() that: Recursively computes left and right subtree heights. Updates the global diameter as the maximum sum of left and right heights. ✨ Example: Input: [1,2,3,4,5] Output: 3 Explanation: The longest path is [4,2,1,3] or [5,2,1,3] ⏱ Time Complexity: O(N) — visit every node once 💾 Space Complexity: O(H) — recursive stack (H = height of tree) 🌱 Key Insight: At each node, the longest path through it is leftHeight + rightHeight. The overall diameter is the maximum of all such paths. 👨💻 GitHub Link: https://lnkd.in/dvUDMZUC #LeetCode #BinaryTree #Recursion #TreeTraversal #DSA #CodingChallenge #C++ #Day112