LeetCode 401: Binary Watch Solution

Day: 52/365 📌 LeetCode POTD: Minimum Operations to Equalize Binary String Level: Hard Key takeaways/Learnings from this problem: 1. This one really makes you think in terms of mismatched positions instead of raw characters. 2. Greedy feels tempting, but you need to carefully compare operation costs before deciding what to fix first. 3. It’s a good reminder that binary string problems often reduce to counting patterns smartly. 4. Biggest takeaway: always try to simplify the string into a difference representation — the solution usually becomes much clearer. #POTD #365DaysOfCode #DSA #Java #ProblemSolving #LearningInPublic #Consistency 🥷

Day 23 of #100DaysOfLeetCode Challenge ✅ 📌 Problem: String to Integer (atoi) – LeetCode #8 📊 Difficulty: Medium 💻 Language: Java Today I solved the classic atoi problem, which focuses on: Handling leading whitespaces Managing + / - signs correctly Converting digits safely Preventing 32-bit integer overflow & underflow ⚡ Performance: Runtime: 1 ms (Beats ~99%) Memory efficient solution This problem really tests edge case handling and string parsing logic, which is crucial for real-world input validation. Consistency over motivation — showing up every day matters. 💪 #Day23 #LeetCode #100DaysOfCode #Java #DSA #ProblemSolving #CodingJourney #Consistency #SoftwareEngineering

Day: 43/365 📌 LeetCode POTD: Binary Number with Alternating Bits Easy Key takeaways/Learnings from this problem: 1. This one shows how clean bit tricks can replace messy string checks when working with binary patterns. 2. Big takeaway: sometimes a small observation (like using XOR or shifting) turns a pattern problem into a super neat one-liner. #POTD #365DaysOfCode #DSA #Java #ProblemSolving #LearningInPublic #Consistency 🥷

Day: 57/365 📌 LeetCode POTD: Special Positions in a Binary Matrix Easy Key takeaways/Learnings from this problem: 1. This one shows how precomputing row and column counts makes checking each cell super easy. 2. Instead of re-scanning the whole row and column every time, count once and reuse smartly. 3. Good reminder that brute force can often be optimized with a tiny bit of preprocessing. 4. Clean implementation and careful condition checking matter more than complex algorithms here. #POTD #365DaysOfCode #DSA #Java #ProblemSolving #LearningInPublic #Consistency 🥷

Day 7/100 – LeetCode Challenge Problem: Palindrome Number Today’s problem focused on number manipulation without converting the integer into a string. Approach: If number is negative → return false Reverse the digits using modulo (% 10) and division (/ 10) Compare reversed number with original number Logic Used: Extract last digit: rem = x % 10 Build reversed number: rev = rev * 10 + rem Remove last digit: x = x / 10 Complexity: Time: O(log₁₀ n) Space: O(1) Key takeaway: Problems involving digits can often be solved mathematically without string conversion. #100DaysOfCode #LeetCode #DSA #Java #ProblemSolving #CodingJourney

🚀 Day 98 of #100DaysOfCode Solved LeetCode #1356 – Sort Integers by The Number of 1 Bits ✅ A clean bit manipulation + sorting problem that rewards thinking beyond plain comparisons. Key Takeaways: -> Using Integer.bitCount() to count set bits efficiently -> Encoding sort priority directly into values for simplicity -> Leveraging built-in sorting for clean and fast solutions -> Small tricks can lead to elegant code ✨ Language: Java -> Runtime: 6 ms (Beats 93.70%) ⚡ -> Memory: 47.42 MB Almost there. Staying consistent till the end 💻🔥 #LeetCode #Java #BitManipulation #Sorting #ProblemSolving #DSA #100DaysOfCode

Day 13/100 – LeetCode Challenge Problem: Linked List Cycle Today’s problem was about detecting whether a cycle exists in a linked list. Approach: Used Floyd’s Cycle Detection Algorithm (Tortoise and Hare). slow pointer moves one step fast pointer moves two steps If a cycle exists, both pointers will eventually meet If fast reaches null, the list has no cycle Complexity: Time: O(n) Space: O(1) Concepts Practiced: Linked List traversal Two-pointer technique Cycle detection algorithm #100DaysOfCode #LeetCode #DSA #Java #LinkedList #ProblemSolving #CodingJourney

Day 14/30 – LeetCode streak Today’s problem: Concatenation of Consecutive Binary Numbers  You need the decimal value of '1' + '2' + '3' + ... + 'n' written in binary back-to-back, all under mod (10^9 + 7). Core trick: treat “concatenate in binary” as shift + OR: * When you append 'i' to the right, you’re really shifting the current result left by 'bits(i)' and OR-ing 'i' into the free space. * The number of bits only increases when 'i' hits a power of two (1, 2, 4, 8, …), so you just track 'bits' and bump it whenever '(i & (i - 1)) == 0'. Day 14 takeaway: Once you see that “stick this binary to the right” is the same as “shift by its bit length and OR”, the whole problem becomes a clean for-loop plus the power-of-two trick—no string building or big integer juggling needed. #leetcode #dsa #java #bitmanipulation #consistency

LeetCode Problem | Binary Watch (401) Solved the Binary Watch problem today using bit manipulation. Problem Statement :- Given a binary watch with LEDs representing hours (0–11) and minutes (0–59), return all possible times where the number of LEDs turned ON equals the given input. 💡 Approach Iterate through all possible hours (0–11) Iterate through all possible minutes (0–59) Use Integer.bitCount() to count number of 1s in binary representation If total set bits = turnedOn, add formatted time to result Bit problems may look small, but they build strong fundamentals in low-level logic. #LeetCode #Java #BitManipulation #ProblemSolving #CodingJourney

Day 39 of Practicing DSA on LeetCode Solved: • (725) Split Linked List in Parts – Medium Focused on: • Calculating the total length of a linked list • Splitting a list into k nearly equal parts • Distributing extra nodes to earlier parts • Managing pointer breaks to avoid unintended links • Practicing careful traversal and list manipulation This problem reinforced an important lesson: Sometimes the challenge isn’t the algorithm — it’s handling edge cases and pointer control correctly. Small pointer mistakes can break the entire list. Consistency over everything. #DSA #Java #LeetCode #LinkedList #ProblemSolving #Consistency #LearningInPublic