Max Non-Negative Product in Matrix with Dynamic Programming

🚀 Day 29 of 100 Days LeetCode Challenge Problem: Check if Strings Can be Made Equal With Operations I Day 29 is a short but pattern + constraint observation problem 🔥 💡 Key Insight: We can only swap characters where: 👉 j - i = 2 For a string of length 4, possible swaps: Index 0 ↔ 2 Index 1 ↔ 3 👉 That means: Positions (0,2) form one group Positions (1,3) form another group 🔍 Core Approach: 1️⃣ Group Characters Extract characters from: Even indices → [0, 2] Odd indices → [1, 3] 2️⃣ Compare Groups Sort both groups for s1 and s2 If both corresponding groups match → ✅ true Else → ❌ false 💡 Why This Works: You can rearrange freely within each group But cannot mix between groups 🔥 What I Learned Today: Limited operations define independent groups Think in terms of index grouping Small problems still test logical clarity 📈 Challenge Progress: Day 29/100 ✅ One day to 30! LeetCode, Strings, Swapping, Greedy, Pattern Recognition, Arrays, DSA Practice, Coding Challenge, Problem Solving #100DaysOfCode #LeetCode #DSA #CodingChallenge #Strings #ProblemSolving #TechJourney #ProgrammerLife #SoftwareDeveloper #CodingLife #LearnToCode #Developers #Consistency #GrowthMindset #InterviewPrep

🚀 Day 19 of 100 Days LeetCode Challenge Problem: Count Submatrices With Equal Frequency of X and Y Today’s problem was a solid combination of 2D Prefix Sum + Hashing concept 🔥 💡 Key Insight: We need submatrices that: Include the top-left cell (0,0) Have equal number of 'X' and 'Y' Contain at least one 'X' 👉 Trick: Convert the grid into values: 'X' → +1 'Y' → -1 '.' → 0 🔍 Core Approach: 1️⃣ 2D Prefix Sum Transformation Build prefix sum based on above conversion 2️⃣ Check Each Submatrix (0,0 → i,j) If sum == 0 → equal number of X and Y ✅ 3️⃣ Extra Condition: Ensure at least one 'X' exists 👉 Track X count separately using another prefix matrix 🔥 What I Learned Today: Transforming problems into numbers simplifies logic Prefix sums + condition checks = powerful combo Always handle extra constraints carefully 📈 Challenge Progress: Day 19/100 ✅ Almost hitting Day 20! LeetCode, Prefix Sum, Matrix, Hashing, Problem Transformation, Algorithms, DSA Practice, Coding Challenge, Problem Solving #100DaysOfCode #LeetCode #DSA #CodingChallenge #PrefixSum #Matrix #Hashing #ProblemSolving #TechJourney #ProgrammerLife #SoftwareDeveloper #CodingLife #LearnToCode #Developers #Consistency #GrowthMindset #InterviewPrep

Day 81 on LeetCode Remove Linked List Elements 🔗🧹✅ Still prioritizing consistency during busy days — and today’s problem was a solid linked list traversal & deletion practice 💯 🔹 Approach Used in My Solution The goal was to remove all nodes with a given value from a linked list. Key idea: • First, handle edge cases where head itself contains the target value • Move head forward until it points to a valid node • Then traverse the list using two pointers:   – prev → last valid node   – temp → current node • If temp->val == val → skip the node by linking prev->next • Otherwise → move both pointers forward This ensures all matching nodes are removed efficiently. ⚡ Complexity: • Time Complexity: O(n) • Space Complexity: O(1) 💡 Key Takeaways: • Practiced pointer manipulation in linked lists • Learned how to safely handle deletions, especially at head • Reinforced importance of edge case handling 🔥 Small consistent steps → strong fundamentals. #LeetCode #DSA #Algorithms #DataStructures #LinkedList #Pointers #ProblemSolving #Coding #Programming #Cpp #STL #SoftwareEngineering #ComputerScience #CodingPractice #DeveloperLife #TechJourney #CodingDaily #Consistency #100DaysOfCode #BuildInPublic #AlgorithmPractice #CodingSkills #Developers #TechCommunity #SoftwareDeveloper #EngineeringJourney

I spent 30 minutes overthinking a problem that had a 2-minute solution. Problem: Construct Uniform Parity Array I At first, it feels like a construction + constraints problem. You start thinking about cases, patterns, edge conditions… But then I stepped back and looked at the operations: nums2[i] = nums1[i] nums2[i] = nums1[i] - nums1[j] (j ≠ i) Now ask a better question: 👉 What happens to parity under these operations? Same value => parity unchanged Difference of two numbers => can be even or odd depending on choice That’s the key. You can control parity freely. Just to make the entire array all even or all odd And that’s always possible. So the answer would be always TRUE . #FirstPrinciples #ProblemSolving #CodingJourney #LeetCode #DSA #Algorithms #SoftwareEngineering #Developers #CodeNewbie #LearnToCode #ProgrammingLife #TechThinking #LogicalThinking #BuildInPublic #DeveloperMindset #CleanThinking #CodingLife #TechCareers #GrowthMindset #ThinkDifferent

“Hard” doesn’t always mean complex logic. Today I solved the Text Justification problem on LeetCode. And it taught me something unexpected. At first glance, it looks like one of those problems where you need some crazy algorithm. But that wasn’t the real challenge. The logic? Pretty straightforward. The real difficulty was something else entirely: → Structuring the output → Handling edge cases → Distributing spaces correctly → Staying patient when everything almost works It wasn’t about intelligence. It was about discipline. Line by line. Case by case. That’s when it hit me: Some “hard” problems aren’t hard because of logic… They’re hard because they test your patience and precision. And honestly, that’s a different kind of skill. If you’re stuck on a problem like this, don’t just think harder. Think calmer. Break it down. Control the structure. And keep going. Have you faced a problem that wasn’t logically hard, but mentally exhausting? Drop it below 👇 #leetcode #dsa #programming #coding #softwareengineering #problemsolving #algorithms #codingjourney #growthmindset #patience #consistency #developers #csstudents

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 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 86 on LeetCode Swapping Nodes in a Linked List 🔗🔄✅ Continuing the linked list journey with another pointer-based thinking problem 💯 🔹 Swapping Nodes in a Linked List The goal was to swap the kth node from the beginning with the kth node from the end. 🔸 Approach Used in My Solution • First, traverse the list to find the total length • Compute the position from the end → k_reverse = n - k + 1 • Traverse again to locate both nodes (swap1 and swap2) • Swap their values instead of changing pointers This keeps the implementation simple while solving the problem correctly. ⚡ Complexity: • Time Complexity: O(n) • Space Complexity: O(1) 💡 Key Takeaways: • Learned how to handle relative positions from start and end • Swapping values can simplify problems where pointer manipulation gets complex • Reinforced multi-pass traversal when needed for clarity 🔥 Step by step building stronger intuition for linked list problems. #LeetCode #DSA #Algorithms #DataStructures #LinkedList #Pointers #ProblemSolving #Coding #Programming #Cpp #STL #SoftwareEngineering #ComputerScience #CodingPractice #DeveloperLife #TechJourney #CodingDaily #Consistency #100DaysOfCode #BuildInPublic #AlgorithmPractice #CodingSkills #Developers #TechCommunity #SoftwareDeveloper #EngineeringJourney

Some problems don’t just test your coding skills — they test your patience. Today was one of those days. I spent hours wrestling with the “Minimum Cost to Cut a Stick” problem. At first glance, it looks manageable. But once you dive in, the complexity unfolds layer by layer — recursion, overlapping subproblems, and finally landing on Dynamic Programming as the only practical way forward. What really stood out to me wasn’t just the solution, but the importance of constraints. I initially underestimated them. Tried approaches that “felt right” but didn’t scale. That’s when it clicked — constraints aren’t just there for formality, they guide your thinking. They tell you whether brute force will fail, whether optimization is necessary, and often hint at the exact paradigm you should be using. After multiple failed attempts, debugging sessions, and rethinking the approach, I finally got it right. And honestly, that moment made the entire struggle worth it. Key takeaway: Don’t ignore constraints. They are often the biggest clue to solving the problem efficiently. Ending the day with a solved problem feels incredibly satisfying. #DataStructures #Algorithms #DynamicProgramming #ProblemSolving #CodingJourney

🚀 Day 45 | 100 Days of Coding Challenge #DrGViswanathanChallenge 📘 Problem Solved: Stock Span Problem (LeetCode) 🔧 Approach Used (Monotonic Stack): • Used a stack to store pairs of {price, span} • For each new price, popped all smaller or equal prices from stack • Accumulated their span to get the current span • Pushed the current price with its computed span 📌 Key Idea: Maintain a decreasing stack so we can efficiently skip previous smaller elements and calculate span in one go. ⏳ Complexity: Time: O(n) amortized Space: O(n) 🧠 Key Learning: Monotonic stack helps optimize problems involving “nearest greater/smaller elements” and avoids redundant comparisons. 💡 Optimization Insight: Instead of checking all previous elements (O(n²)), stack helps compress multiple comparisons into one step. 📂 Topics Covered: Stack, Monotonic Stack, Design #100DaysOfCode #DSA #CPP #LeetCode #CodingJourney #CompetitiveProgramming