Column-Wise Common Prefix Comparison in O(n×m) Time

📌 Problem: Reverse Vowels of a String 💡 Approach: Used the two-pointer technique to reverse only the vowels in the string. Initialize one pointer at the beginning and one at the end. Move both pointers inward until vowels are found, then swap them. Continue this process until both pointers meet. ⚙️ Key Insight: Use a set for fast vowel lookup (O(1)) Two-pointer approach avoids extra space for storing vowels separately ⏱️ Time Complexity: O(n) 📦 Space Complexity: O(n) (due to string → list conversion) 📚 What I learned: Efficient string manipulation using two pointers Optimizing lookups with hash sets #LeetCode #DSA #Algorithms #Coding #ProblemSolving #Python #TwoPointers #InterviewPreparation #CodingJourney

✅ Day 16 of #DSAPrep > Problem: Bubble Sort > Concept: Sorting Algorithm Implemented Bubble Sort by comparing adjacent elements and swapping them if they are in the wrong order. With each iteration, the largest element moves to its correct position at the end of the array. > Key Idea: - Compare adjacent elements - Swap if left element is greater than right - Repeat until the array is sorted > Time Complexity: O(n²) > Space Complexity: O(1) #DSAPrep #Algorithms #Python #Sorting #ProblemSolving #CodingJourney

Search Insert Position: Binary Search with Left Pointer as Insertion Index Standard binary search returns -1 when not found. This variant returns insertion index instead. Key insight: when loop terminates without finding target, left pointer naturally points to where target should be inserted to maintain sorted order. Left Pointer Property: Binary search terminates when l > r. At this point, left has crossed past where target would fit. This makes left the correct insertion index without extra logic. Time: O(log n) | Space: O(1) #BinarySearch #InsertPosition #PointerProperties #SortedArrays #Python #AlgorithmDesign #SoftwareEngineering

Top K Frequent: Bucket Sort Beats Heap with O(n) Time Heap solution costs O(n log k). Bucket sort achieves O(n) by exploiting constraint — frequencies ≤ array length. Index represents frequency, value is list of elements with that frequency. Traverse high-to-low, collecting k elements. Bucket Sort Advantage: When value range is bounded (frequencies ≤ n), bucket sort beats comparison-based sorting. Exploiting constraints transforms complexity. Time: O(n) | Space: O(n) #BucketSort #TopK #FrequencyAnalysis #ComplexityReduction #Python #AlgorithmOptimization #SoftwareEngineering

✅ Day 18 of #DSAPrep > Problem: Insertion Sort > Concept: Sorting Algorithm Learned Insertion Sort, where elements are picked one by one and placed at the correct position in the sorted part of the array. > Key Idea: - Start from second element - Compare with previous elements - Shift elements to insert at correct position > Time Complexity: O(n²) > Space Complexity: O(1) #DSAPrep #Algorithms #Python #Sorting #ProblemSolving #CodingJourney

📌 Problem: Merge Strings Alternately 💡 Approach: Used a simple two-pointer / iteration technique to merge both strings character by character. First, iterate up to the minimum length of both strings and append alternately. Then, append the remaining characters from the longer string. ⚙️ Key Insight: Handle unequal string lengths separately Avoid index out-of-bounds by iterating till min(len(word1), len(word2)) ⏱️ Time Complexity: O(n + m) 📦 Space Complexity: O(n + m) merg 📚 What I learned: String manipulation efficiently Handling edge cases when lengths differ #LeetCode #DSA #Coding #ProblemSolving #Python #SoftwareDevelopment #CodingJourney

Search Insert Position: Binary Search with Fallback to Left Pointer Standard binary search returns -1 when target not found. This variant returns the insertion index instead. The key insight: when the loop terminates without finding target, left pointer naturally points to where target should be inserted to maintain sorted order. Why Left Pointer Works: Binary search terminates when l > r. At this point, left has crossed past the position where target would fit. This property makes left pointer the correct insertion index without extra logic. Time: O(log n) | Space: O(1) #BinarySearch #InsertPosition #PointerProperties #SortedArrays #Python #AlgorithmDesign #SoftwareEngineering

💧 Max Water Problem — Two Pointer Optimization Solved Container With Most Water using the Two Pointer technique in O(n) time. Key Idea: Move the pointer with the smaller height, since it limits the water capacity. 📈 Complexity: Time → O(n) Space → O(1) Small logic shift, big optimization. #DSA #Python #TwoPointers #CodingInterview #Algorithms

💡 Solved Group Anagrams today! 🧠 Key idea: Instead of comparing strings, I used a frequency array (size 26) to create a unique key for each word. ⚠️ Catch in constraints: All characters are lowercase English letters, which allows us to use a fixed-size array of 26 for efficient hashing. 🚀 Result: Achieved O(n · k) time complexity. Great example of converting a comparison problem into a hashing problem! #LeetCode #DSA #Algorithms #Python #CodingInterview

Reorder Linked List: Split, Reverse, Merge Pattern Reordering a linked list looks tricky at first, but it becomes clean once you break it into three deterministic steps: Find the middle Reverse the second half Merge both halves alternately The key insight is: instead of trying to rearrange nodes in one pass, decompose the problem into simpler sub-problems you already know how to solve efficiently. Complexity: Time: O(n) | Space: O(1) Takeaway: Many linked list problems follow a hidden pattern: 👉 Split → Transform → Merge Once you recognize this, problems like palindrome check, reorder list, and even some cycle-based problems become much easier. #LinkedList #TwoPointers #InPlaceAlgorithms #CodingInterview #ProblemSolving #Python #SoftwareEngineering