100 Days LeetCode Challenge: Number of 1 Bits

✅ 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 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 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

🚀 #Day41 of #100DaysOfCode 📌 Problem: 80. Remove Duplicates from Sorted Array II Today’s challenge was about handling duplicates in a sorted array while keeping the array in-place. 💡 Key Idea: The array is already sorted, so duplicates appear next to each other. We need to ensure that each number appears at most twice. Extra duplicates beyond two should be removed while maintaining the original order. 🧠 Approach: 1️⃣ Traverse the array from left to right. 2️⃣ Keep track of how many times the current number appears consecutively. 3️⃣ Allow insertion only if the occurrence count is ≤ 2. 4️⃣ Maintain an index pointer to place valid elements in the correct position. ⚡ Complexity: Time Complexity: O(n) Space Complexity: O(1) (in-place modification) #leetcode #Python #programming #coding #softwaredevelopment #100daysofcode

✅ 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 45 of #100DaysOfCode 📌 Problem: Rotate Array (LeetCode 189) 🔹 Problem Statement: Given an integer array nums, rotate the array to the right by k steps, where k is non-negative. 🔹 Approach: Instead of rotating the array one step at a time, we use the Reverse Technique. Steps: 1️⃣ First calculate k % n to handle large rotations. 2️⃣ Reverse the first part of the array (0 → n-k-1). 3️⃣ Reverse the second part (n-k → n-1). 4️⃣ Finally reverse the entire array. This gives the rotated array efficiently. 🔹 Time Complexity: ⏱️ O(n) 🔹 Space Complexity: 📦 O(1) (In-place rotation) 💡 Key Learning: Using array reversal is a very efficient way to rotate arrays without extra space. #DSA #LeetCode #Python #CodingChallenge #Programming

✅ 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

LeetCode Problem 1680: "Concatenation of consecutive binary numbers": Given an integer n, return the decimal value of the binary string formed by concatenating the binary representations of 1 to n in order, modulo 109 + 7. Approach: Simply initialize a string variable, run loop upto the given value of n, calculate binary representation of each number, convert it to string and concatenate it to the string variable. Convert this result into decimal using int() function and then return value after modulo 10^9 + 7. #Python #LeetCode #CompetitiveProgramming #DailyCoding #Programming #DataStructures #Algorithms #Math #BitManipulation #ProblemSolving

Mastering Sorting Algorithms: A Comprehensive Comparison Guide Sorting is a fundamental operation in computer science, crucial for efficient data processing. This tutorial dives deep into common sorting algorithms, comparing their performance, stability, and use cases through detailed explanations and practical Python code examples. Learn to choose the right algorithm for your specific needs by understanding their strengths and weaknesses. Read the full article 👇 https://lnkd.in/gV3JcuNM #Technology,#Programming,#DataScience,#SoftwareEngineering,#ComputerScience,#SortingAlgorithms,#AlgorithmAnalysis,#PythonCoding,#DataStructures,#AlgorithmPerformance,#FutureOfWork,#DigitalTransformation