LeetCode 03xx
LeetCode problems 300–399
LeetCode 03xx
| # | Problem | Difficulty | Time | Notes |
|---|---|---|---|---|
| 300 | Longest Increasing Subsequence | 🟡 Medium | 1m 18s | The problem asks us to find the length of the longest strictly incr… |
| 301 | Remove Invalid Parentheses | 🔴 Hard | 2m 59s | The problem asks us to remove the minimum number of invalid parenth… |
| 302 | Smallest Rectangle Enclosing Black Pixels | 🔴 Hard | 2m 44s | This problem gives us a binary matrix where each cell contains eith… |
| 303 | Range Sum Query - Immutable | 🟢 Easy | 1m 22s | The problem asks us to design a data structure that supports effici… |
| 304 | Range Sum Query 2D - Immutable | 🟡 Medium | 2m 23s | The problem asks us to design a data structure that can efficiently… |
| 305 | Number of Islands II | 🔴 Hard | 1m 26s | The problem gives us an initially empty m x n grid where every cell… |
| 306 | Additive Number | 🟡 Medium | 1m 24s | The problem asks us to determine whether a given string of digits c… |
| 307 | Range Sum Query - Mutable | 🟡 Medium | 2m 22s | The problem asks us to design a mutable range sum data structure. W… |
| 308 | Range Sum Query 2D - Mutable | 🟡 Medium | 2m 21s | The problem asks us to design a mutable 2D range sum data structure… |
| 309 | Best Time to Buy and Sell Stock with Cooldown | 🟡 Medium | 6m 31s | This problem asks us to maximize profit from stock trading under a … |
| 310 | Minimum Height Trees | 🟡 Medium | 7m 25s | This problem gives us an undirected tree with n nodes labeled from … |
| 311 | Sparse Matrix Multiplication | 🟡 Medium | 1m 43s | This problem asks us to multiply two matrices, but with an importan… |
| 312 | Burst Balloons | 🔴 Hard | 3m 25s | The problem gives us an array nums, where each element represents a… |
| 313 | Super Ugly Number | 🟡 Medium | 3m 19s | This problem asks us to find the nth number in a special sequence c… |
| 314 | Binary Tree Vertical Order Traversal | 🟡 Medium | 1m 11s | The problem asks us to group the nodes of a binary tree by their ve… |
| 315 | Count of Smaller Numbers After Self | 🔴 Hard | 1m 19s | The problem asks us to compute, for every element in the array, how… |
| 316 | Remove Duplicate Letters | 🟡 Medium | 1m 2s | This problem asks us to construct a new string from the input strin… |
| 317 | Shortest Distance from All Buildings | 🔴 Hard | 51s | The problem asks us to find the optimal location to build a house o… |
| 318 | Maximum Product of Word Lengths | 🟡 Medium | 1m 2s | The problem gives us an array of lowercase English words. We need t… |
| 319 | Bulb Switcher | 🟡 Medium | 1m 9s | The problem describes a sequence of n bulbs, all initially turned o… |
| 320 | Generalized Abbreviation | 🟡 Medium | 1m 3s | This problem asks us to generate every possible generalized abbrevi… |
| 321 | Create Maximum Number | 🔴 Hard | 1m 29s | This problem asks us to build the lexicographically largest possibl… |
| 322 | Coin Change | 🟡 Medium | 1m 9s | The problem gives us an array called coins, where each element repr… |
| 323 | Number of Connected Components in an Undirected Graph | 🟡 Medium | 1m 15s | The problem asks us to determine how many connected components exis… |
| 324 | Wiggle Sort II | 🟡 Medium | 1m 10s | The problem asks us to rearrange an array so that it follows a stri… |
| 325 | Maximum Size Subarray Sum Equals k | 🟡 Medium | 1m 13s | The problem asks us to find the longest contiguous subarray whose s… |
| 326 | Power of Three | 🟢 Easy | 1m 11s | The problem asks us to determine whether a given integer n can be r… |
| 327 | Count of Range Sum | 🔴 Hard | 1m 15s | This problem asks us to count how many subarrays have sums that fal… |
| 328 | Odd Even Linked List | 🟡 Medium | 1m 16s | This problem asks us to reorder a singly linked list so that all no… |
| 329 | Longest Increasing Path in a Matrix | 🔴 Hard | 1m 33s | The problem gives us a two-dimensional grid of integers called matr… |
| 330 | Patching Array | 🔴 Hard | 59s | The problem gives us a sorted array of positive integers, nums, and… |
| 331 | Verify Preorder Serialization of a Binary Tree | 🟡 Medium | 1m 8s | The problem gives us a string that represents the preorder serializ… |
| 332 | Reconstruct Itinerary | 🔴 Hard | 1m 4s | The problem is asking us to reconstruct a flight itinerary given a … |
| 333 | Largest BST Subtree | 🟡 Medium | 1m 41s | The problem gives us the root of an arbitrary binary tree and asks … |
| 334 | Increasing Triplet Subsequence | 🟡 Medium | 1m 13s | The problem asks us to determine whether an array contains three nu… |
| 335 | Self Crossing | 🔴 Hard | 1m 17s | The problem describes a path traced on a two-dimensional grid. We b… |
| 336 | Palindrome Pairs | 🔴 Hard | 1m 5s | The problem gives us a list of unique strings called words. We must… |
| 337 | House Robber III | 🟡 Medium | 1m 3s | This problem is a variation of the classic House Robber dynamic pro… |
| 338 | Counting Bits | 🟢 Easy | 1m 4s | The problem asks us to compute the number of set bits, also called … |
| 339 | Nested List Weight Sum | 🟡 Medium | 1m 1s | This problem gives us a special nested data structure called Nested… |
| 340 | Longest Substring with At Most K Distinct Characters | 🟡 Medium | 1m 1s | The problem asks us to find the length of the longest contiguous su… |
| 341 | Flatten Nested List Iterator | 🟡 Medium | 1m 18s | This problem asks us to design an iterator that can traverse a deep… |
| 342 | Power of Four | 🟢 Easy | 1m 10s | This problem asks us to determine whether a given integer n is an e… |
| 343 | Integer Break | 🟡 Medium | 1m 37s | The problem asks us to split a positive integer n into the sum of a… |
| 344 | Reverse String | 🟢 Easy | 1m 1s | The problem asks us to reverse a string that is represented as an a… |
| 345 | Reverse Vowels of a String | 🟢 Easy | 57s | The problem asks us to reverse only the vowels in a string while le… |
| 346 | Moving Average from Data Stream | 🟢 Easy | 50s | The problem asks us to design a data structure that continuously re… |
| 347 | Top K Frequent Elements | 🟡 Medium | 1m 10s | The problem asks us to return the k most frequently occurring eleme… |
| 348 | Design Tic-Tac-Toe | 🟡 Medium | 1m 22s | The problem asks us to design a data structure that simulates an n … |
| 349 | Intersection of Two Arrays | 🟢 Easy | 1m 6s | The problem gives us two integer arrays, nums1 and nums2, and asks … |
| 350 | Intersection of Two Arrays II | 🟢 Easy | 1m 6s | The problem asks us to find the intersection of two integer arrays,… |
| 351 | Android Unlock Patterns | 🟡 Medium | 1m 25s | The problem models the Android lock screen as a 3 x 3 grid containi… |
| 352 | Data Stream as Disjoint Intervals | 🔴 Hard | 1m 20s | This problem asks us to process a stream of non-negative integers a… |
| 353 | Design Snake Game | 🟡 Medium | 1m 23s | The problem asks us to design a mutable data structure that simulat… |
| 354 | Russian Doll Envelopes | 🔴 Hard | 1m 8s | The problem gives a list of envelopes, where each envelope is repre… |
| 355 | Design Twitter | 🟡 Medium | 1m 29s | This problem asks us to design a simplified version of a social med… |
| 356 | Line Reflection | 🟡 Medium | 1m 9s | The problem gives us a collection of points on a 2D plane, where ea… |
| 357 | Count Numbers with Unique Digits | 🟡 Medium | 1m | The problem asks us to count how many integers in the range 0 <= x … |
| 358 | Rearrange String k Distance Apart | 🔴 Hard | 1m 32s | The problem gives us a string s and an integer k. We must rearrange… |
| 359 | Logger Rate Limiter | 🟢 Easy | 1m 6s | The problem asks us to design a logging system that controls how fr… |
| 360 | Sort Transformed Array | 🟡 Medium | 1m 18s | The problem gives us a sorted integer array nums and a quadratic tr… |
| 361 | Bomb Enemy | 🟡 Medium | 33s | The problem presents an m x n matrix called grid where each element… |
| 362 | Design Hit Counter | 🟡 Medium | 1m 25s | The problem asks us to design a data structure that tracks how many… |
| 363 | Max Sum of Rectangle No Larger Than K | 🔴 Hard | 1m 43s | The problem asks us to find the rectangular submatrix whose sum is … |
| 364 | Nested List Weight Sum II | 🟡 Medium | 1m 36s | The problem gives us a nested list structure where each element can… |
| 365 | Water and Jug Problem | 🟡 Medium | 1m 20s | The problem gives us two water jugs with capacities x and y. We can… |
| 366 | Find Leaves of Binary Tree | 🟡 Medium | 1m 13s | The problem asks us to repeatedly remove all leaf nodes from a bina… |
| 367 | Valid Perfect Square | 🟢 Easy | 1m 7s | The problem asks us to determine whether a given positive integer n… |
| 368 | Largest Divisible Subset | 🟡 Medium | 1m 27s | The problem gives us an array of distinct positive integers and ask… |
| 369 | Plus One Linked List | 🟡 Medium | 47s | The problem requires us to add one to a non-negative integer that i… |
| 370 | Range Addition | 🟡 Medium | 1m 26s | The problem gives us an initially zero-filled array of size length.… |
| 371 | Sum of Two Integers | 🟡 Medium | 1m | The problem asks us to compute the sum of two integers without usin… |
| 372 | Super Pow | 🟡 Medium | 1m 18s | The problem asks us to compute: The complication is that the expone… |
| 373 | Find K Pairs with Smallest Sums | 🟡 Medium | 1m 28s | The problem gives us two sorted integer arrays, nums1 and nums2, an… |
| 374 | Guess Number Higher or Lower | 🟢 Easy | 1m 13s | The problem describes a classic interactive guessing game. A hidden… |
| 375 | Guess Number Higher or Lower II | 🟡 Medium | 34s | This problem is a variant of the classic number guessing game with … |
| 376 | Wiggle Subsequence | 🟡 Medium | 1m 9s | The problem asks us to find the length of the longest subsequence i… |
| 377 | Combination Sum IV | 🟡 Medium | 1m 15s | The problem gives us an array of distinct positive integers called … |
| 378 | Kth Smallest Element in a Sorted Matrix | 🟡 Medium | 1m 18s | The problem gives us an n x n matrix where both rows and columns ar… |
| 379 | Design Phone Directory | 🟡 Medium | 1m 11s | The problem asks us to design a data structure that manages a fixed… |
| 380 | Insert Delete GetRandom O(1) | 🟡 Medium | 1m 19s | This problem asks us to design a custom data structure called Rando… |
| 381 | Insert Delete GetRandom O(1) - Duplicates allowed | 🔴 Hard | 1m 28s | The problem asks us to design a data structure called RandomizedCol… |
| 382 | Linked List Random Node | 🟡 Medium | 1m 19s | The problem gives us the head of a singly linked list and asks us t… |
| 383 | Ransom Note | 🟢 Easy | 1m 12s | This problem asks whether it is possible to construct the string ra… |
| 384 | Shuffle an Array | 🟡 Medium | 1m 15s | The problem asks us to design a data structure that supports two op… |
| 385 | Mini Parser | 🟡 Medium | 1m 32s | The problem gives us a string representation of a nested integer st… |
| 386 | Lexicographical Numbers | 🟡 Medium | 1m 22s | The problem asks us to generate all integers from 1 to n, but not i… |
| 387 | First Unique Character in a String | 🟢 Easy | 1m 1s | The problem gives us a string s consisting only of lowercase Englis… |
| 388 | Longest Absolute File Path | 🟡 Medium | 1m 27s | The problem gives us a string representation of a file system hiera… |
| 389 | Find the Difference | 🟢 Easy | 47s | This problem gives us two strings, s and t. The string t is created… |
| 390 | Elimination Game | 🟡 Medium | 1m 6s | The problem gives us a sorted list containing every integer from 1 … |
| 391 | Perfect Rectangle | 🔴 Hard | 1m 33s | This problem asks whether a collection of smaller axis-aligned rect… |
| 392 | Is Subsequence | 🟢 Easy | 1m 8s | The problem asks whether string s can be formed from string t by de… |
| 393 | UTF-8 Validation | 🟡 Medium | 1m 4s | The problem asks us to determine whether a sequence of integers rep… |
| 394 | Decode String | 🟡 Medium | 1m 15s | The problem gives us a string that contains encoded patterns of the… |
| 395 | Longest Substring with At Least K Repeating Characters | 🟡 Medium | 1m 14s | The problem asks us to find the length of the longest substring in … |
| 396 | Rotate Function | 🟡 Medium | 1m 19s | The problem defines a special value called the rotation function fo… |
| 397 | Integer Replacement | 🟡 Medium | 1m 19s | The problem gives us a positive integer n and asks for the minimum … |
| 398 | Random Pick Index | 🟡 Medium | 1m 11s | The problem gives us an integer array nums that may contain duplica… |
| 399 | Evaluate Division | 🟡 Medium | 1m 24s | This problem gives us a collection of equations between variables, … |