LeetCode Challenge: Regular Expression Matching with Dynamic Programming

LeetCode Problem || Find All Possible Stable Binary Arrays II (3130)🚀 🔹 Problem Idea: We are given a number of 0s and 1s and a constraint called limit. The goal is to count the number of possible binary arrays such that no more than limit consecutive identical elements appear. 🔹 Approach: I used Dynamic Programming to track the number of valid arrays formed with: i zeros j ones and the last placed element (0 or 1). The DP state helps ensure that the consecutive limit condition is maintained while building the array. Always enjoying the process of learning and improving problem-solving skills! 💡 #LeetCode #DynamicProgramming #ProblemSolving #Java #CodingPractice #SoftwareEngineering

Solved LeetCode 1009 – Complement of Base 10 Integer today. In simple terms, the problem asks us to flip every bit of a number’s binary representation — change all 0s to 1s and all 1s to 0s — and then convert it back to a decimal number. The key idea was to create a bit mask of all 1s with the same length as the number’s binary form, and then use the XOR (^) operation to flip the bits. A small problem, but a good reminder of how powerful bit manipulation can be in programming. #LeetCode #DSA #Java #CodingJourney #ProblemSolving

🚀 Day 32/180 | #180DaysOfCode 📍 LeetCode | 💻 Java Solved: 6. Zigzag Conversion Simulated the zigzag pattern row by row using an array of StringBuffer objects and appended characters while traversing down and diagonally up. ⏱️ Time Complexity: O(n) 📦 Space Complexity: O(n) Strengthening understanding of string simulation problems and pattern-based traversal. 💪 Consistency continues 🚀 #DSA #LeetCode #Java #CodingJourney #Consistency

💻 Day 8 of #GeekStreak60 🚀 Solved today’s Problem of the Day: Longest Substring with K Unique Characters. 🔎 Problem Idea: Given a string s and an integer k, find the length of the longest substring that contains exactly k distinct characters. If no such substring exists, return -1. 🧠 Approach Used: • Used the Sliding Window technique • Maintained a frequency array to track character occurrences • Expanded the window to include new characters • Shrunk the window whenever distinct characters exceeded k • Updated the maximum length when exactly k unique characters were present ⚡ Key Learning: How the sliding window technique can efficiently handle substring problems involving constraints like distinct characters, reducing time complexity to O(n). Consistency is the goal — learning something new every day! 💪 #geekstreak60 #DSA #Java #SlidingWindow #Strings #ProblemSolving #CodingJourney @geeksforgeeks @NPCI_NPCI

Day 11/100 Day Coding Challenge Today, I solved the LeetCode problem: Container With Most Water using Java. Here’s a detailed breakdown of my approach and learning: Problem Statement: Given an array of non-negative integers representing heights of vertical lines on a coordinate plane, find two lines that, along with the x-axis, form a container that holds the maximum water. Challenges: A brute-force approach would check all possible pairs of lines (O(n²)), which is inefficient for large arrays. I aimed for an optimized solution using the two-pointer technique. Approach (Two-Pointer Technique): Initialize two pointers: l at the start, r at the end of the array. Compute the current area: curWater = (r - l) * min(height[l], height[r]). Update maximum area found so far. Move the pointer pointing to the shorter line inward: If height[l] < height[r], increment l. Else, decrement r. Repeat until the pointers meet. #100DaysOfCode #Java #LeetCode #TwoPointerTechnique #ProblemSolving #Algorithms #SoftwareEngineering #Day11

LeetCode Problem || Check if Binary String Has at Most One Segment of Ones(1784)🚀 we need to check: The string should have only one continuous block of '1's. After a '0' appears, '1' should never appear again. ✨ Insight: Instead of manually counting segments using loops, we can simply check if "01" exists in the string. 📌 Time Complexity: O(n) Practicing problems like these helps improve pattern recognition and problem-solving efficiency. #LeetCode #DSA #Java #CodingPractice #ProblemSolving

Day 9/100 – LeetCode Challenge Problem: 3Sum Today’s challenge was to find all unique triplets in an array whose sum equals 0. Approach: Sort the array to efficiently apply the two-pointer technique. Fix one element nums[i] and use two pointers (left and right) to find the remaining two numbers. If the sum equals 0, store the triplet. Skip duplicate elements to ensure only unique triplets are included. Key Idea: Sorting + Two Pointers helps reduce the brute-force O(n³) approach to O(n²). Concepts Practiced: Sorting Two-pointer technique Duplicate handling Array traversal optimization #100DaysOfCode #LeetCode #DSA #Java #TwoPointers #ProblemSolving #CodingJourney

Day 15 of Programming Multiple Arrays Today I worked on Multiple Arrays and finding the Largest Repeating Element in a Sorted Array. 🔹 Multiple Arrays Learned how to handle and traverse more than one array in a program. This helps when comparing data, merging arrays, or solving problems involving multiple datasets. 🔹 Largest Repeating Element in a Sorted Array Since the array is sorted, repeating elements appear next to each other. By iterating through the array and counting occurrences, we can efficiently identify the largest element that appears more than once. 💡 What I Practiced Traversing multiple arrays Comparing elements across arrays Counting occurrences in sorted arrays Identifying repeating elements using loops and conditions 🧠 Example Problem Practiced Find the largest repeating element in a sorted array. Example: Array → 1 2 2 3 3 3 4 5 Output → 3 (largest element that repeats) #Day15 #ProgrammingJourney #Java #CodingPractice #ProblemSolving

Day 47 – Remove Duplicate Letters Worked on a problem to remove duplicate letters from a string such that every character appears once and the result is the smallest in lexicographical order. Key Learnings: Using a Stack to build the result while maintaining order Applying a greedy approach to remove larger characters when a smaller one appears Tracking character frequency and visited states to ensure correctness #DSA #Java #Stacks #GreedyAlgorithm #ProblemSolving #CodingPractice