Solved Problems (In order)

( ✅ - Implemented solution | ❌ - Not implemented solution | ❓ - Will return | [No emoji] - Generally solved )

Easy (68 Solved)

• 704. Binary Search
• 217. Contains Duplicate
• 219. Contains Duplicate II
• 1. Two Sum
• 242. Valid Anagram
• 14. Longest Common Prefix
• 35. Search Insert Position
• 13. Roman to Integer
• 231. Power of Two (Math✅, Bit Manipulation❌, Recursion❌) ❓
• 9. Palindrome Number
• 342. Power of Four
• 326. Power of Three
• 412. Fizz Buzz
• 258. Add Digits (String✅, Math❌)
• 2264. Largest 3-Same-Digit Number in String
• 58. Length of Last Word
• 2235. Add Two Integers
• 202. Happy Number
• 1323. Maximum 69 Number
• 1281. Subtract the Product and Sum of Digits of an Integer
• 125. Valid Palindrome
• 169. Majority Element
• 268. Missing Number
• 1929. Concatenation of Array
• 26. Remove Duplicates from Sorted Array
• 27. Remove Element
• 69. Sqrt(x)
• 367. Valid Perfect Square
• 3000. Maximum Area of Longest Diagonal Rectangle
• 28. Find the Index of the First Occurence in a String
• 2894. Divisible and Non-Divisible Sum Difference
• 3442. Maximum Difference Between Even and Odd Frequency I
• 278. First Bad Version
• 374. Guess Number Higher or Lower
• 744. Find Smallest Letter Greater Than Target
• 977. Squares of a Sorted Array
• 283. Move Zeroes
• 349. Intersection of Two Arrays (HashSet✅, Sort+Two-Pointers❌) ❓
• 2089. Find Target Indices After Sorting Array (Sort&Iterate✅, Sort+BinarySearch❌) ❓
• 290. Word Pattern
• 344. Reverse String
• 136. Single Number (.count()✅, Bit Manipulation❌) ❓
• 1304. Find N Unique Integers Sum up to Zero
• 1317. Convert Integer to the Sum of Two No-Zero Integers
• 3541. Find Most Frequent Vowel and Consonant
• 1935. Maximum Number of Words You Can Type
• 383. Ransom Note
• 1518. Water Bottles
• 1480. Running Sum of 1d Array
• 303. Range Sum Query
• 724. Find Pivot Index
• 1991. Find the Middle Index in Array (Problem and Solution is the exact same as 724. Find Pivot Index)
• 2389. Longest Subsequence With Limited Sum
• 3354. Make Array Elements Equal to Zero
• 389. Find the Difference
• 3289. The Two Sneaky Numbers of Digitville (2 sneaky bastards have been arrested)
• 3318. Find X-Sum of All K-Long Subarrays I
• 2169. Count Operations to Obtain Zero
• 1437. Check If All 1's Are at Least Length K Places Away
• 717. 1-bit and 2-bit Characters
• 2154. Keep Multiplying Found Values by Two
• 3190. Find Minimum Operations to Make All Elements Divisible by Three
• 1018. Binary Prefix Divisible By 5
• 3512. Minimum Operations to Make Array Sum Divisible by K
• 682. Baseball Game
• 3432. Count Partitions with Even Sum Difference
• 1523. Count Odd Numbers in an Interval Range
• 1925. Count Square Sum Triples

Medium (51 Solved)

• 49. Group Anagrams
• 128. Longest Consecutive Sequence
• 347. Top K Frequent Elements (Sorting✅, Heap(Priority Queue)❌, Bucket Sort❌, Quick Select(Partial Sort)❌, Counter's most_common()❌) ❓
• 53. Maximum Subarray
• 229. Majority Element II (Frequency Count✅, Boyer-Moore's Majority Vote Algorithm✅)
• 36. Valid Sudoku
• 167. Two Sum II - Input Array Is Sorted (HashMap✅, Two Pointers✅, Binary Search✅)
• 3100. Water Bottles II
• 11. Container With Most Water
• 238. Product of Array Except Self
• 560. Subarray Sum Equals K
• 523. Continuous Subarray Sum
• 974. Subarray Sums Divisible by K
• 209. Minimum Size Subarray Sum
• 2125. Number of Laser Beams in a Bank
• 1248. Count Number of Nice Subarrays
• 187. Repeated DNA Sequences
• 3. Longest Substring Without Repeating Characters
• 413. Arithmetic Slices
• 442. Find All Duplicates in an Array
• 3217. Delete Nodes From Linked List Present in Array ❓
• 2257. Count Unguarded Cells in the Grid ❓
• 1749. Maximum Absolute Sum of Any Subarray (Kadane's ✅, Prefix Sum ✅)
• 395. Longest Substring with At Least K Repeating Characters (Sliding Window ✅, Divide and Conquer ❌) ❓
• 1578. Minimum Time to Make Rope Colorful (Sliding Window+Greedy ✅, Two Pointers ✅)
• 1769. Minimum Number of Operations to Move All Balls to Each Box
• 1493. Longest Subarray of 1's After Deleting One Element (Sliding Window + Prefix Sum ✅, Dynamic Programming ❌) ❓
• 2958. Length of Longest Subarray With at Most K Frequency
• 3607. Power Grid Maintenance ❓
• 3254. Find the Power of K-Size Subarrays I
• 3255. Find the Power of K-Size Subarrays II
• 3297. Count Substrings That Can Be Rearranged to Contain a String I
• 535. Encode and Decode TinyURL (System Design Problem)
• 150. Evaluate Reverse Polish Notation
• 1441. Build an Array With Stack Operations
• 2390. Removing Stars From a String
• 3542. Minimum Operations to Convert All Elements to Zero ❓
• 474. Ones and Zeroes ❓
• 1381. Design a Stack With Increment Operation (100th problem)
• 2654. Minimum Number of Operations to Make All Array Elements Equal to 1
• 3228. Maximum Number of Operations to Move Ones to the End ❓
• 2536. Increment Submatrices by One
• 1513. Number of Substrings With Only 1s
• 1262. Greatest Sum Divisible by Three
• 1015. Smallest Integer Divisible by K
• 1930. Unique Length-3 Palindomic Subsequences
• 3381. Maximum Subarray Sum With Length Divisible by K ❓
• 3234. Count the Number of Substrings With Dominant Ones ❓
• 1590. Make Sum Divisible by P
• 2211. Count Collisions on a Road
• 3531. Count Covered Buildings

Hard (6 Solved)

• 3321 Find X-Sum of All K-Long Subarrays II ❓
• 2528. Maximize the Minimum Powered City ❓
• 1611. Minimum One Bit Operations to Make Integers Zero ❓
• 2435. Paths in Matrix Whose Sum is Divisible by K ❓
• 2872. Maximum Number of K-Divisible Components ❓
• 757. Set Intersection Size At Least Two (Sort + Greedy ✅)