Solved LeetCode Daily: XOR After Range Multiplication Queries with Brute Force

Day 89 on LeetCode Valid Parentheses 🧠🧱✅ A fundamental problem that builds strong intuition for stack-based thinking. 🔹 Approach Used in My Solution • Traverse the string character by character • Push all opening brackets onto the stack • For every closing bracket:   – Check if stack is empty → invalid   – Compare with top element   – If mismatch → return false • At the end → stack should be empty for a valid string ⚡ Complexity: • Time Complexity: O(n) • Space Complexity: O(n) 💡 Key Takeaways: • Stack is perfect for handling nested structures • Order and matching are crucial in such problems • Always check for empty stack before accessing top 🔥 Simple problem, but a powerful pattern used in many advanced scenarios. #LeetCode #DSA #Algorithms #DataStructures #Stack #ValidParentheses #ProblemSolving #Coding #Programming #Cpp #STL #SoftwareEngineering #ComputerScience #CodingPractice #DeveloperLife #TechJourney #CodingDaily #Consistency #100DaysOfCode #BuildInPublic #AlgorithmPractice #CodingSkills #Developers #TechCommunity #SoftwareDeveloper #EngineeringJourney

Day 69 on LeetCode Search in Rotated Array (Brute Force Insight) 🔍✅ Today’s problem initially felt tricky, but turned out to be one of the simplest when approached directly. 🔹 Approach Used in My Solution Instead of overcomplicating with rotation logic, I used a straightforward linear search. Key idea: • Traverse the array from start to end • Compare each element with the target • Return the index once found, otherwise -1 Sometimes, the simplest approach is the most reliable. 🔹 Initial Thought Process (Overthinking Phase 😅) • Considered rotating the array and then searching • Thought about adjusting indices using formulas like:   (index - rotation + n) % n • But realized that all of this is unnecessary for basic search ⚡ Complexity: • Time Complexity: O(n) • Space Complexity: O(1) 💡 Key Takeaways: • Not every problem needs an optimized approach — clarity > complexity • Avoid overengineering when a simple solution works perfectly • Always validate if a direct approach solves the problem efficiently enough 🔥 Great reminder: Sometimes the “easy way” is the smart way. #LeetCode #DSA #Algorithms #DataStructures #Arrays #LinearSearch #ProblemSolving #Coding #Programming #Cpp #STL #SoftwareEngineering #ComputerScience #CodingPractice #DeveloperLife #TechJourney #CodingDaily #100DaysOfCode #BuildInPublic #AlgorithmPractice #CodingSkills #Developers #TechCommunity #SoftwareDeveloper #EngineeringJourney

💡 I spent 20 minutes overthinking a simple problem… …and the solution was just one loop. 😅 💻 LeetCode #2452 — Words Within Two Edits At first, I thought: 👉 “I need to transform strings, try all possibilities…” But that was completely unnecessary ❌ 🔍 Then I noticed something simple: 👉 I don’t need to change the string 👉 I just need to compare it ⚙️ Actual logic: Compare two words character by character Count differences If differences ≤ 2 → valid ✅ ⚡ Optimization: The moment differences > 2 → stop checking 🚀 🧠 Big Lesson: Most problems are not hard. We just make them hard by overthinking. 🔥 Keep it simple. Think clearly. Code smart. Have you ever overcomplicated a problem like this? 🤔 #LeetCode #DSA #Algorithms #Cpp #Programming #ProblemSolving #CodingJourney #Developers #TechSkills

🧠 One small mistake can break your entire logic. Today I learned this while solving a grid problem 👇 💻 LeetCode #1559 — Detect Cycles in 2D Grid At first glance, it looks like a simple DFS problem… But there’s a catch ⚠️ 🔍 Common mistake developers make: 👉 “If I visit an already visited cell → cycle exists” Sounds correct… but it’s NOT ❌ 🚀 My Approach (DFS + Parent Tracking): Traverse the grid using DFS Move in 4 directions (up, down, left, right) Only move to cells with the same character 👉 While moving, I track the parent cell 💡 Key Logic: If I reach a cell that is: Already visited AND not the parent 👉 Then a cycle exists ✅ ⚙️ Why parent check is important? Because going back to the previous cell is normal 👉 It should NOT be treated as a cycle 🧠 Takeaway: In DSA, logic rarely fails… 👉 Edge cases do 🔥 The difference between wrong and correct solution is often just one condition Have you ever fixed your solution by changing just 1 line? 😄 #LeetCode #DSA #Algorithms #Programming #Debugging #ProblemSolving #Developers #CodingJourney

Day 88 on LeetCode Add Two Numbers 🔗➕💡 A classic linked list problem focusing on digit-wise addition with carry handling. 🔹 Approach Used in My Solution • Traverse both linked lists simultaneously • Maintain a carry variable for overflow • Add corresponding node values + carry • Create new nodes for result using a dummy head • Continue until both lists and carry are fully processed ⚡ Complexity: • Time Complexity: O(max(n, m)) • Space Complexity: O(max(n, m)) 💡 Key Takeaways: • Dummy node simplifies linked list construction • Carry handling is the core concept in this problem • Reinforces simulation of real-world arithmetic using linked lists 🔥 Another step forward in strengthening pointer-based problem solving. #LeetCode #DSA #Algorithms #DataStructures #LinkedList #AddTwoNumbers #CarryLogic #ProblemSolving #Coding #Programming #Cpp #STL #SoftwareEngineering #ComputerScience #CodingPractice #DeveloperLife #TechJourney #CodingDaily #Consistency #100DaysOfCode #BuildInPublic #AlgorithmPractice #CodingSkills #Developers #TechCommunity #SoftwareDeveloper #EngineeringJourney

Day 91 on LeetCode —Final Prices With a Special Discount 🛒💸✅ Today’s problem focused on array traversal and discount simulation logic. not apply stack because my array logic works equally fine 🔹 Approach Used in My Solution • Traverse each item in the prices array • Search on the right side for the first smaller or equal value • Apply that value as a discount • Store updated answers directly in the result array Simple, clean, and easy to understand. ⚡ Complexity: • Time Complexity: O(n²) • Space Complexity: O(n) 💡 Key Takeaways: • Sometimes a direct array traversal approach explains the logic more clearly • Focused on building the solution step-by-step instead of forcing optimization immediately • Even brute force approaches strengthen understanding of problem flow and conditions 🔥 Consistency and clarity in logic matter just as much as optimization. #LeetCode #DSA #Algorithms #DataStructures #Arrays #ProblemSolving #Coding #Programming #Cpp #STL #SoftwareEngineering #ComputerScience #CodingPractice #DeveloperLife #TechJourney #CodingDaily #Consistency #100DaysOfCode #BuildInPublic #AlgorithmPractice #CodingSkills #Developers #TechCommunity #SoftwareDeveloper #EngineeringJourney

Minimum Distance Between Three Equal Elements Thought process 🤔 Brute force: Run 3 loops, pick every (i, j, k), check if elements are equal, and calculate the absolute difference of indices. Keep updating the minimum. Simple approach, but yeah… O(n³) is too slow when input size grows 😅 How to optimize:: We only care about indices where values are the same, so instead of checking every triplet, let’s store them.. Use a map For each elem, store all its indices Then check only valid triplets from those indices, compute distances for valid groups and track the mini. O(n) time 💡 #leetcode #potd #programming #dsa #developer #softwareengineer #datastructures #algorithms 

💡 I thought this problem needed nested loops but it turned out to be a prefix sum trick 😮 💻 LeetCode #2615 — Sum of Distances At first, I tried checking all pairs ❌ 👉 O(n²)… not scalable Then I noticed something important 👇 🔍 Same values repeat → group their indices Example: 1 → [0,2,3] Now instead of recomputing distances, 👉 we calculate them incrementally ⚙️ Approach: Group indices using hashmap Traverse left → right (prefix sum) Traverse right → left (suffix sum) ⚡ Complexity improved: 👉 O(n²) → O(n) 🧠 Big Lesson: When you see repeated values… 👉 Think grouping + prefix sums That’s where optimization hides 🔥 🚀 This is the kind of thinking that levels up your DSA game Have you used prefix sums in a tricky way like this? 🤔 #LeetCode #DSA #Algorithms #Programming #ProblemSolving #Developers #CodingJourney #Cpp #TechSkills

Day 77 on LeetCode Find Smallest Letter Greater Than Target 🔤🔍✅ Continuing the streak with a clean Binary Search application — keeping things simple and consistent during mids 💯 🔹 Approach Used in My Solution The goal was to find the smallest character strictly greater than the target in a sorted array, with wrap-around behavior. Key idea: • Apply binary search on the sorted array • Whenever letters[mid] > target, store it as a potential answer • Move left to find an even smaller valid character • If no such character exists, return letters[0] (wrap-around case) This ensures we always get the next greatest letter efficiently. ⚡ Complexity: • Time Complexity: O(log n) • Space Complexity: O(1) 💡 Key Takeaways: • Practiced binary search for “next greater element” problems • Learned how to handle wrap-around edge cases • Reinforced writing clean and optimized search logic 🔥 Small wins every day consistency is the real progress. #LeetCode #DSA #Algorithms #DataStructures #BinarySearch #Arrays #ProblemSolving #Coding #Programming #Cpp #STL #SoftwareEngineering #ComputerScience #CodingPractice #DeveloperLife #TechJourney #CodingDaily #Consistency #100DaysOfCode #BuildInPublic #AlgorithmPractice #CodingSkills #Developers #TechCommunity #SoftwareDeveloper #EngineeringJourney

Day 65 on LeetCode Sort Characters By Frequency 🔤📊✅ Today’s problem focused on combining hash maps with custom sorting. 🔹 Approach Used in My Solution The goal was to sort characters in a string based on their frequency in descending order. Key idea in the solution: • Use a hash map to count frequency of each character • Store (character, frequency) pairs in a vector • Apply custom sorting based on frequency (descending order) • Build the result string by repeating characters according to their frequency This approach efficiently organizes characters by importance (frequency). ⚡ Complexity: • Time Complexity: O(n log n) (due to sorting) • Space Complexity: O(n) 💡 Key Takeaways: • Practiced frequency counting using hash maps • Learned how to apply custom comparators in sorting • Reinforced building results based on frequency-driven logic #LeetCode #DSA #Algorithms #DataStructures #HashMap #Sorting #Strings #ProblemSolving #Coding #Programming #Cpp #STL #SoftwareEngineering #ComputerScience #CodingPractice #DeveloperLife #TechJourney #CodingDaily #100DaysOfCode #BuildInPublic #AlgorithmPractice #CodingSkills #Developers #TechCommunity #SoftwareDeveloper #EngineeringJourney