LeetCode: Reverse String in JavaScript with In-Place Approach

🔥 Most developers know .flat() exists. Very few know how to implement it from scratch. I just wrote a deep-dive on Flattening Nested Arrays in JavaScript — including the one approach that will impress any interviewer. Here's what's inside: → What nested arrays actually look like in memory → Why you need flattening in real projects (API responses, grouped data) → 4 different approaches: .flat(), .flatMap(), reduce + concat, recursive spread → The iterative stack approach — no recursion, no stack overflow risk → 6 common interview scenarios with the exact problem-solving mindset If you've ever written a nested forEach inside another forEach — this blog is for you. Read the full blog here 👇 🔗 https://lnkd.in/gSvQRSxi Check out my Hashnode profile 👇 🔗 https://lnkd.in/gAwxuryw hashtag #JavaScript #WebDevelopment #CodingInterview #Programming #piyushgarg #chaicode #hiteshchoudhary

🚀 LeetCode Problem Solved - Best Time to Buy and Sell Stock Today I solved the Best Time to Buy and Sell Stock problem on LeetCode using JavaScript with an optimized single-pass approach. 📊 Approach The goal is to determine the maximum profit from buying and selling a stock given its daily prices. The key idea is to: • Track the minimum price encountered so far • Calculate the potential profit for each day • Update the maximum profit whenever a higher profit is found This allows us to compute the result in one pass through the array. ⚡ Complexity 🔹 Time Complexity: O(n) – Traverse the prices array once 🔹 Space Complexity: O(1) – No extra data structures used ✅ Result ✔️ All test cases passed 📦 Constant space complexity Problems like this reinforce the importance of array traversal, state tracking, and optimizing brute-force solutions into efficient linear algorithms. Consistent practice with these problems strengthens DSA fundamentals and problem-solving skills for coding interviews. #leetcode #javascript #dsa #algorithms #codingpractice #softwareengineering #webdevelopment

When Prefix Sums Repeat, Something Interesting Happens 🔁📊 Solved LeetCode 523 today. Problem 🔍 Check if a subarray of length ≥ 2 exists whose sum is divisible by k. Initial thought 🧠 Check every subarray using prefix sums. But that quickly becomes O(n²). Better approach 🚀 Use Prefix Sum + Remainder HashMap. Store the first index where each remainder appears. If the same remainder appears again and currentIndex - previousIndex >= 2, a valid subarray exists. Mental model 🧩 If: prefix[j] % k = prefix[i] % k Then: prefix[j] - prefix[i] is divisible by k. Interview takeaway 🎯 Subarray + divisibility → Prefix Sum + Remainder tracking. Practical insight 💡 Store the first occurrence of each remainder to maximize subarray length detection. This same pattern appears in problems like 974 and 560. #DSA #LeetCode #Algorithms #PrefixSum #HashMap #JavaScript #CodingInterview #InterviewPrep

📌 #69 DailyLeetCodeDose Today's problem: 25. Reverse Nodes in k-Group – 👹 Hard Interesting fact about me – linked lists were my favorite topic in the Algorithms and Data Structures course at university. So for the 69th problem I got something special – a hard linked list problem 😈 Honestly, the problem description is written in probably the most confusing way possible. But the core idea is actually pretty simple: you just need to reverse nodes in groups of size k inside the list. In practice, this is only slightly more complicated than reversing the entire linked list – the main difference is that when you reverse a group, you must keep track of the new head of that reversed group so you can correctly reconnect it with the previous and next parts of the list. It may look scary at first glance, but in reality it's not that bad. The most important thing is not to get lost in pointer manipulation 🦍 https://lnkd.in/daAPrhbP #DailyLeetCodeDose #LeetCode #JavaScript #Algorithms #ProblemSolving #Coding

Ever heard of function composition? It's like stacking functions together to create new ones! 🎉 Imagine transforming data in a seamless flow, just like a chain reaction. For instance, let's say you have an array of numbers and you want to double them and then add one. Instead of writing multiple loops, we can compose functions to simplify our code. Exciting, right? 😄 Have you ever used function composition in your projects? How did it change the way you write code? #JavaScript #Coding #FunctionComposition #WebDevelopment #ProgrammingTips

Solving the Top K Frequent Elements Problem in JavaScript One of the classic algorithm problems you’ll encounter while preparing for coding interviews is Top K Frequent Elements. The goal is simple: Given an array of numbers, return the k most frequent elements. Example: topKFrequent([1,2,2,3,3,3],2) // Output: [3,2] Here’s a clean and readable approach using frequency counting + sorting: How it works Count how many times each number appears Convert the object into an array Sort elements by frequency Return the top k elements 📚 I'm currently building a repository with multiple JavaScript pattern exercises and algorithm solutions. Check it out here: 👉 https://lnkd.in/ej4fNeZs #JavaScript #Algorithms #CodingInterview #DataStructures #SoftwareEngineering #LeetCode #Programming

Priority Order in JavaScript Day 216 Today Today I learned about the Priority Queue. It is a very important concept in data structures. In a normal queue the rule is first in first out. But in a priority queue the element with the highest priority is processed first. Think of a hospital emergency room. A patient with a serious injury gets treated before someone with a cold even if the person with the cold arrived earlier. This is exactly how a priority queue works. I learned that there are two ways to implement this. You can use an array and sort it every time but that is slow. The best way is using a Heap. Using a Heap makes adding and removing elements very fast because the time complexity is log n. JavaScript does not have a built in priority queue like some other languages. This means we have to build it ourselves using classes. This is a great way to practice logic building and understand how things work under the hood. A very helpful tip for interviews is that if a question asks for the Kth smallest or Kth largest element you should think of using a priority queue or a heap. It makes the solution much more efficient. Today I solved these LeetCode questions: 215 Kth Largest Element in an Array 703 Kth Largest Element in a Stream #DSAinJavaScript #365daysOfCoding #JavaScriptLogic #LeetCode #DataStructures #PriorityQueue #CodingInterview #ProgrammingDaily #SoftwareEngineering #TechLearning #WebDevelopment #LogicBuilding #ProblemSolving #JavaScriptDev #JSCode #ArrayLogic #HeapDataStructure #AlgorithmDesign #CodingChallenge #BinaryHeap

Just solved a classic algorithm problem and recorded my approach. I started with a linear search (O(n)) solution — simple, clear, and a great baseline for understanding the problem. Walking through it step by step really helped reinforce how time complexity grows with input size. Then I explored how to improve it to O(log n) using binary search when the array is sorted — a great reminder of how powerful optimization can be. Key takeaway: Start with a working solution Then optimize for performance Sharing my thought process in this video — would love your feedback and how you usually approach problems like this. #coding #javascript #algorithms #leetcode #softwareengineering #100daysofcode

🚀 Just Uploaded a New LeetCode Solution! Solved LeetCode #26 – Remove Duplicates from Sorted Array using the Two Pointer Technique in JavaScript. This is a must-know pattern for coding interviews — simple idea, but very powerful when applied correctly. 👉 In this video, I’ve covered: Intuition behind the problem Step-by-step dry run Optimal in-place solution (O(n) time, O(1) space) Clean and easy-to-understand JavaScript code 🔗 Watch here: https://lnkd.in/g-HgkGXQ If you're preparing for coding interviews or strengthening your DSA fundamentals, this one is definitely worth your time. Would love to hear your approach to this problem — drop it in the comments 👇 #leetcode #dsa #codinginterview #javascript #twopointer #programming #softwaredevelopment #coding #developers #learning #jdcodebase

Maps and Sets in JavaScript: A Deep Dive JavaScript provides several ways to store and manage data, with objects and arrays being the most commonly used structures. However, when dealing with unique values or key-value pairs with better effi... Read more → https://lnkd.in/dvP2-4nH #TheCampusCoders #Tech #Developers #Programming #WebDev