Day 11: Sliding Window Problems Clarified

🚀 𝗗𝗮𝘆 𝟭𝟲/𝟯𝟬 — 𝗗𝗦𝗔 𝗖𝗵𝗮𝗹𝗹𝗲𝗻𝗴𝗲 Day 16, and linked lists are officially testing my patience… and my pointer accuracy There’s something humbling about working with nodes — one small mistake and suddenly your list disappears into the void. But once the logic clicks, it’s actually pretty satisfying. Today was all about careful pointer manipulation and thinking a few steps ahead instead of just moving forward blindly. 🔎 𝗗𝗮𝘆 𝟭𝟲 𝗙𝗼𝗰𝘂𝘀 • Managing multiple pointers safely • Handling edge cases • Solved: ✅ Merge Two Sorted Lists ✅ Remove Nth Node From End ✅ Palindrome Linked List Big takeaway: with linked lists, confidence is good… but double-checking your pointers is better Still showing up. Still improving. On to Day 17 #DSA #Python #LeetCode #Consistency #SoftwareEngineering #ProblemSolving

Day 4/100: Mastering the Two-Pointer Shuffle 🚀 💡 How I solved it: I used the Two-Pointer Technique to move all zeros to the end of an array while maintaining the original order of other elements. *Pointer i: Tracks the next position for a non-zero element. *Pointer j: Scans through the entire array. *The Swap: Every time j finds a non-zero value, it swaps with i. This effectively "bubbles" all zeros to the back in a single pass. 🧠 Key Takeaway: *Efficiency: Achieved O(n) time complexity and O(1) space (In-place modification). *Relative Order: This method ensures that non-zero numbers stay in their original sequence without needing extra memory or hash maps. The logic is getting sharper every day! 📈 #DSA #Python #100DaysOfCode #ProblemSolving #StriverA2Z

🐍 Your Date Column isn't a Date It just looks like one. 2026-01-15 stored as a string will pass every visual check — and silently break every time-based analysis you run. Ask these before you trust a date column: ✅ What dtype is it actually? ✅ How was it parsed? → Is 01/02/2026 January 2nd or February 1st? ✅ What timezone is it in? → UTC? Local server time? → Two timestamps can look identical and be 5 hours apart. ✅ What does a missing date mean? → Event didn't happen? Wasn't recorded? Pipeline failed? 👉 Always validate with two lines of code — it can save hours of debugging. What's the messiest date column you've encountered? 👇 #DataAnalytics #Python #AnalyticsThinking

🗓️ #Day_95 of #DilipSolvesDSA 💻 Problem: Integer to Roman Numeral Conversion 🧠 Approach: 1. Break number into place values → Example: 3749 = 3000 + 700 + 40 + 9 2. Handle special cases (4 & 9) → Use subtractive notation: IV, IX, XL, XC, CD, CM 3. Convert remaining values → Pick the largest Roman symbol ≤ current number → Subtract and repeat 💡 Key Insight: → 49 is not written as "49" → It becomes 40 + 9 → XL + IX 🚀 Progress: 95 days down. Still going strong. 💪 #DSA #LeetCode #Python #100DaysOfCode #Consistency #ProblemSolving

🚀 Day 51 of #100DaysOfCode 📌 LeetCode 567 – Permutation in String 🔍 Problem Understanding We are given two strings s1 and s2. The task is to check whether any permutation of s1 exists as a substring in s2. In simple terms: If we rearrange the characters of s1, can we find that arrangement inside s2? 💡 Approach / Intuition The efficient way to solve this problem is using the Sliding Window Technique. Steps of thinking: 1️⃣ Count the frequency of characters in s1. 2️⃣ Create a window in s2 with the same size as s1. 3️⃣ Move the window one character at a time across s2. 4️⃣ For each window, compare the character frequencies with s1. 5️⃣ If the frequencies match, it means a permutation of s1 exists in s2. ⚡ Key Concepts Used Sliding Window Hash Map / Character Frequency Count String Traversal 📊 Complexity ⏱ Time Complexity: O(n) 💾 Space Complexity: O(1) (since character set is fixed) #Day51 #100DaysOfCode #LeetCode #DSA #Python #CodingJourney #ProblemSolving #SlidingWindow

🚀 𝗗𝗮𝘆 𝟭𝟵/𝟯𝟬 — 𝗗𝗦𝗔 𝗖𝗵𝗮𝗹𝗹𝗲𝗻𝗴𝗲 Day 19 and today’s focus was on Binary Search Trees (BST). What makes BST problems interesting is how their ordered structure can simplify searching and comparisons. Once the properties of a BST are clear, many operations become much more intuitive. Today was about understanding how to navigate and use that structure effectively. 🔎 𝗗𝗮𝘆 𝟭𝟵 𝗙𝗼𝗰𝘂𝘀 • Understanding BST properties • Practicing efficient tree traversal for search operations • Solved: ✅ Search in a Binary Search Tree ✅ Insert into a Binary Search Tree ✅ Lowest Common Ancestor of a BST One thing this challenge keeps reinforcing: the right data structure often makes the solution much simpler. Still learning. Still improving. On to Day 20 #DSA #Python #LeetCode #Consistency #SoftwareEngineering #ProblemSolving

🚀 𝗗𝗮𝘆 𝟮𝟯/𝟯𝟬 — 𝗗𝗦𝗔 𝗖𝗵𝗮𝗹𝗹𝗲𝗻𝗴𝗲 Day 23 and continuing deeper into graph problems. The interesting part about graphs is how many real-world systems they represent — networks, dependencies, routes, and connections. Problems start to feel more like exploring a map than just working through a list. Today’s focus was on using traversal techniques to explore nodes and understand relationships between them. 🔎 𝗗𝗮𝘆 𝟮𝟯 𝗙𝗼𝗰𝘂𝘀 • Strengthening DFS and BFS traversal • Understanding how to track visited nodes • Solved: ✅ Clone Graph ✅ Course Schedule ✅ Rotting Oranges Graph problems definitely require careful thinking, but it’s satisfying when the traversal logic finally clicks. On to Day 24 #DSA #Python #LeetCode #Consistency #SoftwareEngineering #ProblemSolving

🚀 Day 55 of #100DaysOfCode Solved LeetCode 350 – Intersection of Two Arrays II today! 🔍 Problem Insight: Given two arrays, we need to return their intersection such that each element appears as many times as it occurs in both arrays. 💡 Approach Used: - Used "Counter" (hash map) to store frequency of elements from first array - Traversed second array and matched elements - Reduced count after every match to handle duplicates correctly ⚡ Why this works: Efficient frequency tracking avoids nested loops and reduces time complexity. 🧠 Complexity: - Time: O(n + m) - Space: O(n) ✅ Key Learning: Hashing + frequency counting is powerful for problems involving duplicates and intersections. 🔥 Consistency is the key — showing up every day! #DSA #LeetCode #Python #CodingJourney #PlacementPrep #SoftwareEngineering #100DaysOfCode

60 Days of Problem Solving Challenge - Day 27 👉 Today’s Problem: Vertical Tree Traversal (Binary Tree) The goal was to print the vertical order traversal of a binary tree from the leftmost vertical line to the rightmost. 💡 Approach / Logic: Used Level Order Traversal (BFS) with a queue. Assigned each node a Horizontal Distance (HD) from the root: Root → HD = 0 Left child → HD − 1 Right child → HD + 1 Stored nodes in a hashmap/dictionary where: HD → list of node values BFS ensures nodes in the same vertical line appear in level order. Finally, sorted the horizontal distances and printed values from leftmost to rightmost column. This problem reinforced concepts of Binary Trees, BFS traversal, and mapping nodes using horizontal distance. 📈 Progress Update 🔥 Current Streak: 27 Days 🎯 Goal: 60 Days of Consistent Problem Solving #60DaysOfCode #GeeksforGeeks #DSA #BinaryTree #ProblemSolving #Python #CodingJourney #Consistency

🚀 #100DaysOfCode – Day 37 🔍 LeetCode 387 – First Unique Character in a String Today’s problem was about finding the first non-repeating character in a string and returning its index. 🧠 Problem Summary Given a string s, return the index of the first unique character. If no such character exists, return -1. 💡 Approach 1️⃣ Create a frequency dictionary to count occurrences of each character. 2️⃣ Traverse the string again and return the first index where frequency == 1. 3️⃣ If none found → return -1. ⏱️ Complexity 🕒 Time Complexity: O(n) 📦 Space Complexity: O(1) (since only lowercase letters) 🔥 Key Learning Two-pass hashmap technique Importance of frequency counting Clean and readable implementation Consistency > Motivation 💪. #Day37 #LeetCode #Python #DSA #CodingJourney #ProblemSolving #100DaysOfCode