Min Changes to Alternating Binary String

k-th Lexicographical Happy String of Length n🪢 Given n and k, return the k-th lexicographical happy string of length n. Thought process Brute force idea: Generate all possible happy strings of length n, Sort them, Return the string at k-1 index Optimization Instead of generating everything and sorting later, we can control the order while generating. During backtracking: Try characters in order → a, b, c Skip if the current character is the same as the previous one This way strings are already generated in lexicographical order, so we can directly return the k-th string. #leetcode #thoughtProcess #problemSolving #programming #recursion #backtracking

Leetcode POTD : Find Unique Binary Strings... Given an array that contains n unique binary strings, each of length n, and some possible strings are missing. Target: find a binary string of length n that is not present in the array. Thought process... Initially I thought of generating all possible binary strings of length n. Since the constraint was small, it passed all the test cases. But then I felt generating all 2^n strings just to find one missing is not really optimal, so I started thinking about a better approach 🤔 If we observe the examples carefully, we notice something interesting. There are n strings and each string has length n. Ohh yes, here is the trick 👀 Since the ansmust also be a string of length n, we can construct a new one ourselves. All the given strings are already unique, so if we flip the bit at index i from the i-th string (0 -> 1 or 1 -> 0), the newly formed string will differ from every string at least at one position. That guarantees the string will be unique and missing from the array ✨ Using this idea, the missing binary string can be found in O(n) time. #leetcode #potd #binary #strings #programming #problem_solving #consistency

Multithreading in theory vs reality 🧵⚙️ In theory: Every thread executes independently, efficiently, and peacefully. In reality: Race conditions, deadlocks, and thread competition, context switching, synchronization issues etc. 👉 Writing multithreaded code is easy. 👉 Writing correct multithreaded code is the real challenge. #Multithreading #Programming #SoftwareEngineering #BackendDevelopment #CPP #CppProgramming #ModernCPP #Multithreading #Concurrency #ParallelProgramming #SystemProgramming #SoftwareEngineering #CodingLife

Multithreading in theory vs reality 🧵⚙️ In theory: Every thread executes independently, efficiently, and peacefully. In reality: Race conditions, deadlocks, and thread competition, context switching, synchronization issues etc. 👉 Writing multithreaded code is easy. 👉 Writing correct multithreaded code is the real challenge. #Multithreading #Concurrency #Programming #SoftwareEngineering #BackendDevelopment #CPP #CppProgramming #ModernCPP #Multithreading #Concurrency #ParallelProgramming #STL #SystemProgramming #SoftwareEngineering #CodingLife

C++ | Arrays | Sum of Array Elements 🧠 Problem: Given an array, find the sum of all elements. 💻 Approach: Iterate through the array and keep adding each element to a running sum. ⏱ Time Complexity: O(n) 📦 Space Complexity: O(1) 📂 Explore more: #CPPProblems #Arrays #CodingPractice #DSA #Programming 📌 Follow QSolutions for daily coding practice 🚀

📂 [Arrays Series] Practice in Multiple Languages 🚀 Solve the same problem in different languages 👇 🐍 Python Solution: https://lnkd.in/ekim7PZ8 💼 Java https://lnkd.in/eyBiE2gn ⚡ C++ Solution: https://lnkd.in/ev2YmG5k 💡 Try all versions to strengthen your logic across languages 📂 Explore more: #PythonProblems #CPPProblems #JavaProblems #Arrays 📌 Follow QSolutions for daily coding practice 🚀

I wrote a beginner-friendly article explaining 10 Pattern Problems in C++ with diagrams and code. Pattern problems are a great way to improve logic and understanding of loops. Check it out here: https://lnkd.in/grVA7Ggb #Programming #CPP #Coding

#Day58 Solved: Longest Substring Without Repeating Characters(Leetcode 3) Worked on one of the most asked string problems that really tests problem-solving and optimization skills. Problem: Find the length of the longest substring without repeating characters. Approach: Used the sliding window technique to efficiently track a valid substring. Instead of checking all possible substrings (which is slow), I dynamically adjusted the window: Expanded when characters were unique Shrunk when a duplicate appeared Key Learning: The biggest takeaway was understanding how to maintain a valid window rather than restarting every time a duplicate is found. Complexity: Optimized the solution from O(n²) to O(n) using the right approach. This problem strengthened my understanding of: Sliding Window Two Pointer Technique Optimizing brute force solutions #leetcode #dsa #programming #coding #slidingwindow #problemSolving

DAY->12 Solved Running Sum of 1d Array on LeetCode today. Implemented the solution using the Prefix Sum technique to compute the cumulative sum of elements efficiently. -> Time Complexity: O(n) -> Space Complexity: O(n) All 54/54 test cases passed with 0 ms runtime. Small problems like this help strengthen fundamentals in arrays and prefix sums, which are widely used in many algorithmic problems. #LeetCode #DSA #CodingJourney #Programming #Cplusplus #ProblemSolving

42 of #100DaysOfCode Solved LeetCode 930 – Binary Subarrays With Sum 💡 Today’s problem was a great example of how powerful Prefix Sum + HashMap can be when dealing with subarrays. 🔹 Approach Used: Instead of checking all subarrays (which would be inefficient), I used a running prefix sum and stored its frequency in a hashmap. This reduces the time complexity to O(n) — much more efficient than brute force! ⚡ 🔹 What I Learned: Prefix sum helps convert subarray problems into lookup problems HashMap optimizes repeated computations Always think: “Can I store previous results to save time?” #LeetCode #DSA #CodingJourney #Programming #Cpp #SoftwareEngineering #ProblemSolving #LearnToCode