Palindrome Number Challenge: Easy Two-Pointer Scan

Day 30 of #30DaysOfCode with Educative Challenge: Continuous Subarray Sum (Medium) Core Idea: Detect a subarray whose sum is a multiple of a given number The Pattern: Running total with remainder tracking Why It Works Here: Keep a running total while walking through the array and record the first position where each remainder (after dividing by the given number) appears. When the same remainder shows up again at least two positions later, it means the numbers between those two positions add up to a value that fits the requirement. Production Lesson: This pattern is useful whenever repeated “states” over a stream need to be detected quickly. Log analysis, rolling counters, or anomaly detection can often be reduced to tracking how cumulative values repeat over time instead of re-scanning all ranges. Edge Worth Remembering: Storing an initial remainder state at a virtual index before the array starts allows subarrays beginning at the first element to be handled cleanly. #Educative #Python #SoftwareEngineering #ContinuousLearning #ProblemSolving

LeetCode Journey 🚀 | Solved Problem #9 – Palindrome Number ✅ Just solved LeetCode Problem 9 – Palindrome Number ✅ 📌 Key learnings from this problem: Understood how to check palindromes without converting to string Learned the importance of edge cases (negative numbers, numbers ending with 0) Practiced reversing only half of the number for better optimization This problem helped me improve my logical thinking and confidence in handling conditions step by step. Small progress, but moving forward consistently 💪 #LeetCode #DSA #ProblemSolving #LearningJourney #Consistency #CareerRestart #Python https://lnkd.in/gK7nVYjV

Day 4/100 – #100DaysOfLeetCode 🚀 🧩 Problem: LeetCode 125 – Valid Palindrome (Easy) 🧠 Approach: Convert the string to lowercase, then remove all non-alphanumeric characters. Compare the cleaned string with its reverse. If both are the same, the string is a palindrome. 💻 Solution: class Solution:   def isPalindrome(self, s: str) -> bool:     s = "".join(char for char in s.lower() if char.isalnum())     return s==s[::-1] ⏱ Time | Space: O(n) | O(n) 📌 Key Takeaway: Preprocessing strings makes palindrome checks clean and easy to implement. #leetcode #dsa #python #codingchallenge #problemSolving

Day 91: Minimum Window Substring 🪟 This "Hard" problem yields to a Sliding Window! We track characters we have vs. what we need using frequency maps. Expand r to find a valid window, then shrink l to find the smallest possible substring. O(n) efficiency! 🚀 #Day91 #SlidingWindow #LeetCode #Python #DSA #Coding #100DaysOfCode #Algorithm

Daily LeetCode Progress | Day 14✅ LeetCode #3 | Longest Substring Without Repeating Characters ✔️ 🧠 Approach: • Applied a sliding window (two pointers) technique to maintain a substring with all unique characters. • Used a set to track characters in the current window for constant-time duplicate checks. • When a duplicate was encountered, shifted the left pointer until the window became valid again 🔁 • Continuously updated the maximum window size while expanding the right pointer for optimal results 📈 ⏱️ Time Complexity: O(n) 📦 Space Complexity: O(n) “Efficiency is not about doing more, it’s about doing it right.” #LeetCode #DataStructures #SlidingWindow #Python #Consistency

🚀 Day 6 of LeetCode | Integer to Roman Today’s challenge was Integer to Roman — converting a given integer into its Roman numeral representation. Approach: Use predefined integer values and their Roman symbols Apply a greedy strategy to subtract the largest possible value Handle subtractive cases like IV, IX, XL, XC Build the result step by step until the number becomes zero ⏱ Time Complexity: O(1) 📦 Space Complexity: O(1) #LeetCode#DSA #ProblemSolving #Python #CodingJourney

🚀 DSA Practice – Daily Progress 📌 Problem: Sort an array of 0s, 1s, and 2s (without using built-in sort) Today I solved a classic DSA problem using the Dutch National Flag algorithm. 🔍 Approach: Used three pointers (low, mid, high) Segregated 0s, 1s, and 2s in a single pass Achieved in-place sorting with constant extra space ⏱ Complexity: Time: O(n) Space: O(1) 📖 Key Takeaway: Simple pointer-based greedy strategies can lead to highly efficient solutions when constraints are well understood. #DSA #ProblemSolving #Python #Algorithms #CodingPractice #GeeksforGeeks #LearningJourney

✨ Day 69 of #100DaysOfDSA 📌 LeetCode 961: N-Repeated Element in Size 2N Array A neat problem that highlights how problem constraints can guide us to an optimal solution. 🧩 Problem Insight: The array has 2n elements Only one element repeats n times The rest appear exactly once 🧠 Approach & How It Works: Use a hash set to track visited elements Traverse the array once The first element that appears again must be the answer due to the given constraints ⚡ This guarantees a single-pass solution with immediate detection. ⚙️ Performance: 🚀 Runtime: 0 ms (beats 100%) 📦 Memory: 13.28 MB (beats 85.16%) ✅ Testcases Passed: 103 / 103 📘 What I Learned: ✔ Leveraging problem constraints for faster solutions ✔ Efficient use of hash sets ✔ Writing clean O(n) time complexity code ✔ Early exit strategies for optimization Consistency > Motivation. One problem at a time 💪 #LeetCode #DSA #Array #RepeatedElements #100DaysOfDSA #100DaysOfCode #Python #ProblemSolving #CodingPractice #TechJourney

Day 93: Evaluate Reverse Polish Notation 🧮 Use a Stack to process postfix notation! Push numbers onto the stack; when you hit an operator, pop the last two values, apply the operation, and push the result back. Note: for subtraction and division, operand order matters! ⚡ #Day93 #Stack #Algorithm #Python #RPN #Coding #LeetCode #100DaysOfCode

Day 34 ✅ | Residue Prefixes (LeetCode 3803) Solved this string problem by tracking distinct characters in each prefix and comparing it with the prefix length modulo 3. The solution runs in linear time and demonstrates how simple math and set-based tracking can make prefix problems efficient and elegant. #Python #LeetCode #Strings #PrefixSum #HashSet #ProblemSolving #Day34 #CodingJourney