LeetCode 3713: Longest Balanced Substring Challenge

✅ Day 63 of 100 Days LeetCode Challenge Problem: 🔹 #1758 – Minimum Changes To Make Alternating Binary String 🔗 https://lnkd.in/gSY9BDhw Learning Journey: 🔹 Today’s problem focused on converting a binary string into an alternating pattern with minimum changes. 🔹 There are only two valid alternating patterns: starting with '0' (0101...) or starting with '1' (1010...). 🔹 I counted mismatches for both patterns while iterating through the string. 🔹 The answer is the minimum number of flips required between the two possibilities. Concepts Used: 🔹 String Traversal 🔹 Pattern Matching 🔹 Greedy Counting 🔹 Parity Indexing Key Insight: 🔹 When only two structural patterns are possible, evaluate both and choose the minimum cost. 🔹 Index parity (i % 2) is a clean way to enforce alternating constraints. 🔹 Comparing against expected patterns avoids unnecessary string reconstruction. #LeetCode #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #SoftwareDeveloper #ProblemSolving #Programming #ComputerScience #TechCareers #100DaysOfCode #DailyCoding #Consistency #LearningInPublic #Python #BackendDevelopment #InterviewPreparation #TechCommunity

✅ Day 46 of 100 Days LeetCode Challenge Problem: 🔹 #91 – Decode Ways 🔗 https://lnkd.in/gpZQshBr Learning Journey: 🔹 Today’s problem focused on counting the number of ways to decode a numeric string into letters. 🔹 I used a Dynamic Programming approach with space optimization, tracking only the previous two states. 🔹 At each step, I checked both single-digit and two-digit decoding possibilities. 🔹 Careful handling of edge cases like leading zeros was essential to ensure valid decoding paths. Concepts Used: 🔹 Dynamic Programming 🔹 Space Optimization 🔹 String Parsing 🔹 State Transition Key Insight: 🔹 Many decoding problems depend on evaluating valid transitions from previous states. 🔹 Maintaining only necessary previous results reduces space complexity to O(1). 🔹 Edge cases involving zeros are critical in avoiding invalid combinations. #LeetCode #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #SoftwareDeveloper #ProblemSolving #Programming #ComputerScience #TechCareers #100DaysOfCode #DailyCoding #Consistency #LearningInPublic #Python #BackendDevelopment #InterviewPreparation #TechCommunity

✅ Day 58 of 100 Days LeetCode Challenge Problem: 🔹 #1680 – Concatenation of Consecutive Binary Numbers 🔗 https://lnkd.in/gt22hnfF Learning Journey: 🔹 Today’s problem involved concatenating the binary representations of numbers from 1 to n. 🔹 I generated binary strings using bin(i)[2:] and appended them sequentially. 🔹 After forming the final binary string, I converted it back to an integer. 🔹 Since the result can be very large, I applied modulo 10**9+7. Concepts Used: 🔹 Binary Representation 🔹 String Manipulation 🔹 Modular Arithmetic 🔹 Simulation Key Insight: 🔹 Direct string concatenation works but is not optimal for large n. 🔹 Efficient solutions avoid large intermediate strings by using bit shifts and modular arithmetic at each step. 🔹 Understanding bit-length growth is crucial for optimization in binary construction problems. #LeetCode #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #SoftwareDeveloper #ProblemSolving #Programming #ComputerScience #TechCareers #100DaysOfCode #DailyCoding #Consistency #LearningInPublic #Python #BackendDevelopment #InterviewPreparation #TechCommunity

✅ Day 61 of 100 Days LeetCode Challenge Problem: 🔹 #260 – Single Number III 🔗 https://lnkd.in/gKWtdDrb Learning Journey: 🔹 Today’s problem focused on finding the two elements that appear only once in an array where all others appear twice. 🔹 I used a frequency counting approach with Counter to track occurrences. 🔹 Then, I iterated through the dictionary and collected elements with frequency equal to 1. 🔹 This straightforward method ensures correctness with clear logic. Concepts Used: 🔹 Hash Map / Dictionary 🔹 Frequency Counting 🔹 Array Traversal 🔹 Filtering Logic Key Insight: 🔹 Hash-based counting simplifies duplicate detection problems. 🔹 When constraints allow extra space, clarity can be prioritized over bit-level optimization. 🔹 This problem also has an advanced XOR-based O(1) space solution, but counting keeps the implementation simple and readable. #LeetCode #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #SoftwareDeveloper #ProblemSolving #Programming #ComputerScience #TechCareers #100DaysOfCode #DailyCoding #Consistency #LearningInPublic #Python #BackendDevelopment #InterviewPreparation #TechCommunity

✅ Day 54 of 100 Days LeetCode Challenge Problem: 🔹 #728 – Self Dividing Numbers 🔗 https://lnkd.in/gxraQJ82 Learning Journey: 🔹 Today’s problem focused on identifying numbers that are divisible by each of their digits. 🔹 For every number in the given range, I extracted its digits and checked divisibility conditions. 🔹 Any number containing zero was immediately rejected since division by zero is invalid. 🔹 Valid numbers were collected into the final result list. Concepts Used: 🔹 Digit Extraction 🔹 Modulo Arithmetic 🔹 Iterative Checking 🔹 Conditional Filtering Key Insight: 🔹 Breaking numbers into digits simplifies many number-theory problems. 🔹 Early elimination (like handling zeros) improves efficiency. 🔹 Clear validation logic makes implementation straightforward and readable. #LeetCode #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #SoftwareDeveloper #ProblemSolving #Programming #ComputerScience #TechCareers #100DaysOfCode #DailyCoding #Consistency #LearningInPublic #Python #BackendDevelopment #InterviewPreparation #TechCommunity

✅ Day 59 of 100 Days LeetCode Challenge Problem: 🔹 #3857 – Minimum Cost to Split into Ones 🔗 https://lnkd.in/g-7ARYJV Learning Journey: 🔹 Today’s problem focused on minimizing the total cost of splitting an integer n into n ones. 🔹 Each split divides a number x into a and b such that a + b = x, with cost a × b. 🔹 The key observation is that splitting as evenly as possible at every step minimizes the total accumulated cost. 🔹 This creates a divide-and-conquer pattern where balanced partitions reduce overall multiplication cost. Concepts Used: 🔹 Greedy Strategy 🔹 Divide and Conquer 🔹 Mathematical Cost Analysis 🔹 Stack / Simulation Approach Key Insight: 🔹 Balanced splits minimize product cost at each stage. 🔹 The total minimum cost follows a structured pattern based on recursive halving. 🔹 Recognizing optimal partitioning significantly simplifies the solution logic. #LeetCode #WeeklyContest #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #ProblemSolving #100DaysOfCode #CompetitiveProgramming #Python #TechCommunity

✅ Day 56 of 100 Days LeetCode Challenge Problem: 🔹 #24 – Swap Nodes in Pairs 🔗 https://lnkd.in/g6W2b3Fq Learning Journey: 🔹 Today’s problem focused on swapping every two adjacent nodes in a linked list. 🔹 I used an iterative pointer manipulation approach to swap nodes in pairs without modifying node values. 🔹 A prev pointer helped connect previously swapped pairs with the current pair. 🔹 Careful handling of edge cases (empty list or single node) ensured correctness. Concepts Used: 🔹 Linked List Manipulation 🔹 Pointer Rewiring 🔹 Iterative Traversal 🔹 In-place Modification Key Insight: 🔹 Linked list problems often rely entirely on precise pointer updates. 🔹 Keeping track of previous connections prevents breaking the list structure. 🔹 Drawing pointer transitions step-by-step makes implementation much easier. #LeetCode #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #SoftwareDeveloper #ProblemSolving #Programming #ComputerScience #TechCareers #100DaysOfCode #DailyCoding #Consistency #LearningInPublic #Python #BackendDevelopment #InterviewPreparation #TechCommunity

✅ Day 51 of 100 Days LeetCode Challenge Problem: 🔹 #973 – K Closest Points to Origin 🔗 https://lnkd.in/gzp_xraa Learning Journey: 🔹 Today’s problem focused on finding the k points closest to the origin in a 2D plane. 🔹 I calculated the squared Euclidean distance for each point to avoid unnecessary square root operations. 🔹 Using a min-heap, I efficiently retrieved the smallest distances. 🔹 A hashmap helped group points with the same distance, ensuring correct retrieval of coordinates. Concepts Used: 🔹 Heap / Priority Queue 🔹 Euclidean Distance 🔹 Hash Map 🔹 Greedy Selection Key Insight: 🔹 Squared distance is sufficient for comparison and avoids extra computation. 🔹 Heaps are ideal for efficiently extracting the smallest (or largest) k elements. 🔹 Choosing the right data structure significantly simplifies implementation. #LeetCode #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #SoftwareDeveloper #ProblemSolving #Programming #ComputerScience #TechCareers #100DaysOfCode #DailyCoding #Consistency #LearningInPublic #Python #BackendDevelopment #InterviewPreparation #TechCommunity

✅ Day 57 of 100 Days LeetCode Challenge Problem: 🔹 #1404 – Number of Steps to Reduce a Number in Binary Representation to One 🔗 https://lnkd.in/ggb5GXaW Learning Journey: 🔹 Today’s problem focused on reducing a binary number to 1 using specific rules. 🔹 If the number is even, divide it by 2. If it is odd, add 1. 🔹 I converted the binary string to an integer, applied the operation, and converted it back to binary after each step. 🔹 The process continued until the value became "1", counting the total operations. Concepts Used: 🔹 Binary Representation 🔹 Bit Manipulation Concepts 🔹 Simulation 🔹 Conditional Logic Key Insight: 🔹 Binary problems often map directly to parity checks (even vs odd). 🔹 Simulation is straightforward but understanding bit behavior can lead to optimized solutions. 🔹 Recognizing patterns in binary transitions improves problem-solving efficiency. #LeetCode #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #SoftwareDeveloper #ProblemSolving #Programming #ComputerScience #TechCareers #100DaysOfCode #DailyCoding #Consistency #LearningInPublic #Python #BackendDevelopment #InterviewPreparation #TechCommunity

Just solved “Longer Contiguous Segments of Ones than Zeros” on LeetCode with 0 ms runtime ⚡ Instead of storing segments or using extra space, I approached it with a single pass linear scan. 💡 My approach: Maintain two counters: count_1 → current streak of 1s count_0 → current streak of 0s Maintain two variables: maximum_1 → longest contiguous 1s maximum_0 → longest contiguous 0s While iterating through the string: If the character is '1', increase count_1 and reset count_0 If the character is '0', increase count_0 and reset count_1 Continuously update the maximum streaks Finally check if max(1s) > max(0s) ✨ Why this works well Only one traversal O(n) time complexity O(1) space complexity Clean and simple logic Always fascinating how simple state tracking can solve problems efficiently. Back to solving more problems and sharpening problem-solving skills! 🔥 #leetcode #coding #datastructures #algorithms #programming #python #codingpractice #problemSolving #softwareengineering #techlearning #computerscience #developers #100daysofcode #codingjourney #womenintech 🚀