Flatten Binary Tree to Linked List with Iterative Approach

✅ 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

✅ 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 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 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 53 of 100 Days LeetCode Challenge Problem: 🔹 #191 – Number of 1 Bits 🔗 https://lnkd.in/gZPa-tQf Learning Journey: 🔹 Today’s problem focused on counting the number of set bits (1s) in the binary representation of an integer. 🔹 I converted the number to its binary form and iterated through the string representation. 🔹 By counting occurrences of '1', I determined the Hamming weight of the number. 🔹 This approach is simple and clear for understanding bit representation. Concepts Used: 🔹 Bit Manipulation 🔹 Binary Representation 🔹 String Conversion 🔹 Counting Technique Key Insight: 🔹 Every integer can be analyzed at the bit level for efficient computation. 🔹 Converting to binary provides an intuitive way to visualize set bits. 🔹 Bit manipulation problems often have multiple optimized approaches beyond basic counting. #LeetCode #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #SoftwareDeveloper #ProblemSolving #Programming #ComputerScience #TechCareers #100DaysOfCode #DailyCoding #Consistency #LearningInPublic #Python #BackendDevelopment #InterviewPreparation #TechCommunity

✅ Day 40 of 100 Days LeetCode Challenge Problem: 🔹 #1200 – Minimum Absolute Difference 🔗 https://lnkd.in/gdXZxeGh Learning Journey: 🔹 Today’s problem focused on finding all pairs of elements with the minimum absolute difference in an array. 🔹 I first sorted the array so that the smallest differences would appear between adjacent elements. 🔹 By scanning the sorted list once, I tracked the minimum difference and collected all valid pairs. 🔹 This approach avoids unnecessary comparisons and improves efficiency. Concepts Used: 🔹 Sorting 🔹 Greedy Scanning 🔹 Array Traversal 🔹 Optimization Key Insight: 🔹 Sorting simplifies many comparison-based problems. 🔹 Minimum differences in a sorted array will always occur between neighboring elements. 🔹 Maintaining a running minimum helps build the result efficiently in one pass. #LeetCode #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #SoftwareDeveloper #ProblemSolving #Programming #ComputerScience #TechCareers #100DaysOfCode #DailyCoding #Consistency #LearningInPublic #Python #BackendDevelopment #InterviewPreparation #TechCommunity

✅ Day 43 of 100 Days LeetCode Challenge Problem: 🔹 #684 – Redundant Connection 🔗 https://lnkd.in/gWtKJ-FA Learning Journey: 🔹 Today’s problem focused on detecting an extra edge that creates a cycle in an undirected graph. 🔹 I used the Union-Find (Disjoint Set Union) data structure to track connected components. 🔹 For each edge, I checked whether both nodes already belong to the same set. 🔹 If they do, adding that edge forms a cycle, making it the redundant connection. Concepts Used: 🔹 Union-Find (Disjoint Set) 🔹 Path Compression 🔹 Graph Cycle Detection 🔹 Connected Components Key Insight: 🔹 Union-Find provides an efficient way to detect cycles during edge additions. 🔹 Path compression optimizes repeated parent lookups. 🔹 Incrementally building connectivity helps quickly identify redundant edges. #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 50 of 100 Days LeetCode Challenge Problem: 🔹 #696 – Count Binary Substrings 🔗 https://lnkd.in/gqvcumf3 Learning Journey: 🔹 Today’s problem focused on counting substrings where consecutive groups of 0s and 1s have equal length. 🔹 I analyzed transitions between groups of characters and counted valid balanced segments. 🔹 The idea was to track runs of consecutive characters and compare adjacent group lengths. 🔹 By accumulating the minimum of neighboring group sizes, I identified all valid binary substrings. Concepts Used: 🔹 String Traversal 🔹 Two-Pointer / Group Counting 🔹 Pattern Recognition 🔹 Greedy Counting Key Insight: 🔹 Binary substring problems often reduce to analyzing consecutive character groups. 🔹 Instead of checking all substrings, comparing adjacent group sizes gives an efficient solution. 🔹 Recognizing repeating patterns helps avoid brute-force complexity. #LeetCode #DataStructures #Algorithms #CodingInterview #SoftwareEngineering #SoftwareDeveloper #ProblemSolving #Programming #ComputerScience #TechCareers #100DaysOfCode #DailyCoding #Consistency #LearningInPublic #Python #BackendDevelopment #InterviewPreparation #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