Day 2/100 – Move Zeroes Rearrange an array so all 0s go to the end while keeping other elements in order. Brute force vs Two-pointer O(n) time, O(1) space 🎥 Watch full video here: howtoalgo.com/question/2 🌐 howtoalgo.com | All course at ₹2000 #dsa #100daysofcode

Day 3/100 – Validate Subsequence Master the two-pointer technique to check if one array is a subsequence of another, all in O(n) time, O(1) space. Clean logic + dry run included Watch full video: howtoalgo.com/question/3 Learn more at howtoalgo.com #100DaysOfAlgo #DSA

Day 5/100 - Height Checker Sort & count who’s out of order in a line! Brute force: O(n log n) Optimized with counting sort: O(n) 📺Full video: howtoalgo.com/question/5 💻Learn more at howtoalgo.com #100DaysOfAlgo #CodingTips #DSA #HowToAlgo

𝐃𝐚𝐲 𝟔/𝟏𝟎𝟎 - 𝐁𝐢𝐧𝐚𝐫𝐲 𝐓𝐫𝐞𝐞𝐬 Explore types, traversals, search & insert complexities. 𝐖𝐚𝐭𝐜𝐡 𝐭𝐡𝐞 𝐟𝐮𝐥𝐥 𝐯𝐢𝐝𝐞𝐨: howtoalgo.com/question/6 Visit ww.howtoalgo.com Use code 𝐋𝐄𝐕𝐄𝐋𝐔𝐏𝟐𝟎 to get yearly access at just ₹2000 #100DaysOfAlgo #DSA

Day 8/100 – Minimum Absolute Difference Find the closest pairs in a sorted array, efficiently! O(n²) → O(n log n) optimization Sorted results, clean implementation Full video: howtoalgo.com/question/8 Visit - howtoalgo.com #100DaysOfAlgo #CodingChallenge #DSA

Day 9/100 – Check If It Is a Straight Line Combine math + code to check if points lie on a line Learn slope logic, edge case handling & O(1) space efficiency. Watch full video here: howtoalgo.com/question/9 Practice here: howtoalgo.com #DSA #Coding #100DaysOfCode

Day 10/100 – Best Time to Buy and Sell Stock 📈 Maximize profit by tracking min buy price and max sell price in one pass. ⏱️ O(n) time 💡 Core interview question Watch full video here: howtoalgo.com/question/10 Visit - howtoalgo.com #100DaysOfAlgo #DSA #Coding

Day 12/100 - Transpose a Matrix Swap (i, j) → (j, i) and reshape the grid. Learn via dry run, pseudocode, and O(N×M) complexity. Full video: howtoalgo.com/question/12 Practice at howtoalgo.com Use code LEVELUP20 for full access at ₹2000 #DSA #CodingInterview

Day 13/100 Today we use a Trie to crack the Longest Common Prefix problem from names like Spyder & Spywell Key idea: Prefix tree + count tracking Time: O(n × m + L) Practice 👉 howtoalgo.com Watch full video here - howtoalgo.com/question/13 #DSA #100DaysOfCode

Day 14/100 - Find the first index of a substring using Brute Force (O(n×m)) & KMP (O(n+m)) with LPS array. Input: "a-c-a-b-c-a-b-a-b-a-b-d" Sub: "a-b-a-b-d" → Output: 7 Practice at - howtoalgo.com Full video - howtoalgo.com/question/14 #DSA #100DaysOfCode #Coding

Day 16/100 Selection Sort: Find the min, swap, repeat. ✅ Time: O(n²) ✅ Space: O(1) Great for learning sorting fundamentals. Full video: howtoalgo.com/question/16 Practice now at howtoalgo.com Use Code LEVELUP20 for full access @ ₹2000 #DSA #100DaysOfCode #Coding

Day 17/100 - Learn Bubble Sort: easy, visual, beginner-friendly. Optimized early exit version explained! Time: O(n²), Space: O(1) Full video: howtoalgo.com/question/17 Practice now at howtoalgo.com Use code LEVELUP20 for full access at ₹2000 #DSA #LearnToCode

Day 18/100 – Sorting cards = Insertion Sort ✔️ Step-by-step dry run ✔️ Optimized logic ✔️ Time: O(n²), Space: O(1) Great for small/nearly sorted data Full Video -howtoalgo.com/question/18 Practice at howtoalgo.com Use code LEVELUP20 for full access @ ₹2000 #DSA

Day 19/100 – Balanced Brackets – a classic stack Q asked in top tech interviews. Learn the stack logic Dry run walkthrough Code-ready explanation Full video: howtoalgo.com/question/19 Visit howtoalgo.com Use code LEVELUP20 to unlock all at ₹2000 #DSA #100DaysOfCode

Day 20/100 🔁 Remove Duplicates from a Sorted Linked List Efficient O(n) time + O(1) space - no extra memory! Invest in quality, not quantity ▶️ howtoalgo.com 🎟 Code: LEVELUP20 for full access at ₹2000 Full Video: howtoalgo.com/question/20 #DSA #100DaysOfCode

Day 21/100 of #100DaysOfAlgo Reversing a Linked List – a must-know for tech interviews! Learn how 3 pointers & one loop do the magic. O(n) time, O(1) space, clear logic. Practice now: howtoalgo.com Watch Full Video here: howtoalgo.com/question/21 #DSA #100DaysOfCode

Day 25/100 Master Fibonacci: Recursion ❌ → Memoization ✅ → 2-pointer Learn how to move from brute force to brilliance. Practice: howtoalgo.com Use code LEVELUP20 to get all-in-one bundle at ₹2000. Watch full video - howtoalgo.com/question/25 #DSA #100DaysOfCode

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