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Practice › LeetCode › LeetCode 38xx ›

LeetCode 3850 - Count Sequences to K

LeetCode Problem 3850 Difficulty: 🔴 Hard Topics: Array, Math, Dynamic Programming, Memoization, Number Theory Solution LeetCode 3850 - Count Sequences to K Problem Understanding We start with a value val = 1 and process the array from left to right. For every element nums[i] , we must choose exactly one of three actions: Multiply the current value by nums[i] Divide the current value by nums[i] Do nothing Division is exact...

Practice › LeetCode › LeetCode 34xx ›

LeetCode 3459 - Length of Longest V-Shaped Diagonal Segment

LeetCode Problem 3459 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Memoization, Matrix Solution Problem Understanding We are given an n x m matrix whose entries are only 0 , 1 , or 2 . A valid V-shaped diagonal segment must satisfy two independent requirements: First, the values along the path must follow a very specific sequence. The first cell must contain 1 . Every subsequent cell must alternate between 2...

Practice › LeetCode › LeetCode 30xx ›

LeetCode 3040 - Maximum Number of Operations With the Same Score II

LeetCode Problem 3040 Difficulty: 🟡 Medium Topics: Array, Dynamic Programming, Memoization Solution Problem Understanding This problem asks us to determine the maximum number of operations that can be performed on an array of integers, where every operation removes two elements from specific positions (either the first two elements, the last two elements, or the first and last elements), and every operation must produce the same score , defined as the...

Practice › LeetCode › LeetCode 31xx ›

LeetCode 3154 - Find Number of Ways to Reach the K-th Stair

LeetCode Problem 3154 Difficulty: 🔴 Hard Topics: Math, Dynamic Programming, Bit Manipulation, Memoization, Combinatorics Solution Let's dive into a comprehensive solution guide for LeetCode 3154 - Find Number of Ways to Reach the K-th Stair . Problem Understanding This problem involves Alice navigating a staircase starting at stair 1, aiming to reach stair k . The staircase is theoretically infinite, starting at stair 0, and Alice has two operations available:...

Practice › LeetCode › LeetCode 23xx ›

LeetCode 2312 - Selling Pieces of Wood

LeetCode Problem 2312 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Memoization Solution Problem Understanding The problem presents a rectangular piece of wood of size m x n and a list of specific prices for certain subrectangles. Each entry in the prices array, [hi, wi, pricei] , indicates that a piece of wood of height hi and width wi can be sold for pricei dollars. You may make any number of...

Practice › LeetCode › LeetCode 23xx ›

LeetCode 2318 - Number of Distinct Roll Sequences

LeetCode Problem 2318 Difficulty: 🔴 Hard Topics: Dynamic Programming, Memoization Solution Problem Understanding The problem is asking us to compute the total number of distinct sequences of dice rolls of length n that satisfy two constraints: the greatest common divisor (GCD) of any two consecutive rolls must be 1 , and any repeated value in the sequence must be separated by at least two rolls. In other words, if a...

Practice › LeetCode › LeetCode 20xx ›

LeetCode 2019 - The Score of Students Solving Math Expression

LeetCode Problem 2019 Difficulty: 🔴 Hard Topics: Array, Hash Table, Math, String, Dynamic Programming, Stack, Memoization Solution LeetCode 2019, The Score of Students Solving Math Expression Problem Understanding The problem gives us a mathematical expression string s containing only: Single digit numbers 0-9 Addition operators + Multiplication operators * The expression is guaranteed to be valid. For example: 3+5*2 7+3*1*2 Students were supposed to evaluate the expression using the correct...

Practice › LeetCode › LeetCode 18xx ›

LeetCode 1857 - Largest Color Value in a Directed Graph

LeetCode Problem 1857 Difficulty: 🔴 Hard Topics: Hash Table, String, Dynamic Programming, Graph Theory, Topological Sort, Memoization, Counting Solution Problem Understanding The problem asks us to find the largest color value along any path in a directed graph of n nodes, where each node has a color represented by a lowercase English letter. The graph may contain cycles, in which case the function should return -1 . The input consists...

Practice › LeetCode › LeetCode 28xx ›

LeetCode 2876 - Count Visited Nodes in a Directed Graph

LeetCode Problem 2876 Difficulty: 🔴 Hard Topics: Dynamic Programming, Depth-First Search, Graph Theory, Topological Sort, Memoization Solution Problem Understanding The problem presents a directed graph with n nodes, where each node has exactly one outgoing edge defined by the array edges . Specifically, edges[i] indicates that there is a directed edge from node i to node edges[i] . The task is to simulate a traversal starting from each node: you...

Practice › LeetCode › LeetCode 29xx ›

LeetCode 2920 - Maximum Points After Collecting Coins From All Nodes

LeetCode Problem 2920 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Bit Manipulation, Tree, Depth-First Search, Memoization Solution LeetCode 2920 - Maximum Points After Collecting Coins From All Nodes Problem Understanding We are given a tree with n nodes rooted at node 0 . Each node contains a certain number of coins. We must collect coins from every node while respecting the tree hierarchy, meaning a node can only be processed...

Practice › LeetCode › LeetCode 29xx ›

LeetCode 2998 - Minimum Number of Operations to Make X and Y Equal

LeetCode Problem 2998 Difficulty: 🟡 Medium Topics: Dynamic Programming, Breadth-First Search, Memoization Solution Problem Understanding The problem asks us to transform an integer x into another integer y using the minimum number of operations. At every step, we are allowed to perform exactly one of four actions: Divide x by 11 if it is divisible by 11 . Divide x by 5 if it is divisible by 5 . Decrease...

Practice › LeetCode › LeetCode 23xx ›

LeetCode 2311 - Longest Binary Subsequence Less Than or Equal to K

LeetCode Problem 2311 Difficulty: 🟡 Medium Topics: String, Dynamic Programming, Greedy, Memoization Solution Problem Understanding The problem asks us to find the length of the longest subsequence of a given binary string s such that the resulting binary number is less than or equal to a given integer k . A subsequence is any selection of characters from s in their original order, possibly skipping some. Importantly, leading zeros are...

Practice › LeetCode › LeetCode 27xx ›

LeetCode 2713 - Maximum Strictly Increasing Cells in a Matrix

LeetCode Problem 2713 Difficulty: 🔴 Hard Topics: Array, Hash Table, Binary Search, Dynamic Programming, Memoization, Sorting, Matrix, Ordered Set Solution Problem Understanding The problem gives us an m x n matrix where each cell contains an integer value. We may start from any cell, and from the current cell we are allowed to move only within the same row or the same column. However, there is an important restriction: we...

Practice › LeetCode › LeetCode 23xx ›

LeetCode 2328 - Number of Increasing Paths in a Grid

LeetCode Problem 2328 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort, Memoization, Matrix Solution Problem Understanding In this problem, we are given a two dimensional matrix called grid . Each cell contains a positive integer. From any cell, we may move in four directions: up, down, left, or right. Diagonal movement is not allowed. The goal is to count how many strictly increasing...

Practice › LeetCode › LeetCode 19xx ›

LeetCode 1900 - The Earliest and Latest Rounds Where Players Compete

LeetCode Problem 1900 Difficulty: 🔴 Hard Topics: Dynamic Programming, Memoization Solution Problem Understanding The tournament is organized as a sequence of elimination rounds. In every round, players are paired symmetrically from the two ends of the current lineup. The first player faces the last player, the second player faces the second-to-last player, and so on. If the number of players is odd, the middle player advances automatically without playing. The...

Practice › LeetCode › LeetCode 15xx ›

LeetCode 1553 - Minimum Number of Days to Eat N Oranges

LeetCode Problem 1553 Difficulty: 🔴 Hard Topics: Dynamic Programming, Memoization Solution LeetCode 1553 - Minimum Number of Days to Eat N Oranges Problem Understanding This problem asks us to compute the minimum number of days required to eat exactly n oranges, given three possible actions that can be performed each day. On any single day, we may choose one of the following operations: Eat exactly one orange. If the current...

Practice › LeetCode › LeetCode 14xx ›

LeetCode 1444 - Number of Ways of Cutting a Pizza

LeetCode Problem 1444 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Memoization, Matrix, Prefix Sum Solution Edit LeetCode 1444 - Number of Ways of Cutting a Pizza Problem Understanding This problem asks us to count the number of valid ways to divide a rectangular pizza into exactly k pieces such that every piece contains at least one apple. The pizza is represented as a grid of characters where 'A' indicates an...

Practice › LeetCode › LeetCode 09xx ›

LeetCode 964 - Least Operators to Express Number

LeetCode Problem 964 Difficulty: 🔴 Hard Topics: Math, Dynamic Programming, Memoization Solution Problem Understanding This problem asks us to construct a mathematical expression using only the number x repeatedly, combined with the operators + , - , * , and / , such that the final expression evaluates exactly to target . The challenge is not simply reaching the target value, but doing so with the minimum number of operators....

Practice › LeetCode › LeetCode 15xx ›

LeetCode 1575 - Count All Possible Routes

LeetCode Problem 1575 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Memoization Solution LeetCode 1575 - Count All Possible Routes Problem Understanding This problem gives us a set of cities positioned on a number line. The array locations stores the coordinate of each city, where locations[i] represents the position of city i . We are also given: start , the index of the city where we begin finish , the index...

Practice › LeetCode › LeetCode 15xx ›

LeetCode 1569 - Number of Ways to Reorder Array to Get Same BST

LeetCode Problem 1569 Difficulty: 🔴 Hard Topics: Array, Math, Divide and Conquer, Dynamic Programming, Tree, Union-Find, Binary Search Tree, Memoization, Combinatorics, Binary Tree Solution Problem Understanding The problem gives us a permutation of integers from 1 to n , and we insert the numbers into an initially empty Binary Search Tree (BST) in the exact order they appear in the array. A BST has the following property: Values smaller than...

Practice › LeetCode › LeetCode 05xx ›

LeetCode 509 - Fibonacci Number

LeetCode Problem 509 Difficulty: 🟢 Easy Topics: Math, Dynamic Programming, Recursion, Memoization Solution Problem Understanding This problem asks us to compute the n th Fibonacci number. The Fibonacci sequence is defined recursively. The first two numbers are fixed: F(0) = 0 F(1) = 1 Every value after that is calculated as the sum of the previous two values: F(n) = F(n - 1) + F(n - 2) Given an integer...

Practice › LeetCode › LeetCode 01xx ›

LeetCode 140 - Word Break II

LeetCode Problem 140 Difficulty: 🔴 Hard Topics: Array, Hash Table, String, Dynamic Programming, Backtracking, Trie, Memoization Solution Problem Understanding The problem asks us to segment a given string s into all possible sentences where each word in the sentence exists in a given dictionary wordDict . Essentially, we need to find all ways to insert spaces into the string such that every resulting substring is a valid dictionary word. The...

Practice › LeetCode › LeetCode 06xx ›

LeetCode 698 - Partition to K Equal Sum Subsets

LeetCode Problem 698 Difficulty: 🟡 Medium Topics: Array, Dynamic Programming, Backtracking, Bit Manipulation, Memoization, Bitmask Solution Problem Understanding The problem is asking whether an array of integers nums can be divided into exactly k subsets such that each subset has the same sum. The input consists of the integer array nums and the integer k . The expected output is a boolean value: true if such a partitioning is possible,...

Practice › LeetCode › LeetCode 17xx ›

LeetCode 1728 - Cat and Mouse II

LeetCode Problem 1728 Difficulty: 🔴 Hard Topics: Array, Math, Dynamic Programming, Graph Theory, Topological Sort, Memoization, Matrix, Game Theory Solution Problem Understanding This problem describes a two-player perfect-information game played on a small grid. One player controls the mouse and the other controls the cat. Both players move optimally and alternate turns, with the mouse always moving first. The grid contains several kinds of cells: 'M' represents the mouse's starting...

Practice › LeetCode › LeetCode 16xx ›

LeetCode 1659 - Maximize Grid Happiness

LeetCode Problem 1659 Difficulty: 🔴 Hard Topics: Dynamic Programming, Bit Manipulation, Memoization, Bitmask Solution Problem Understanding This problem asks us to place introverts and extroverts inside an m x n grid in a way that maximizes the total happiness score. Every grid cell can either remain empty, contain one introvert, or contain one extrovert. We are allowed to leave some people unused, so we do not necessarily have to place...

Practice › LeetCode › LeetCode 04xx ›

LeetCode 488 - Zuma Game

LeetCode Problem 488 Difficulty: 🔴 Hard Topics: String, Dynamic Programming, Stack, Breadth-First Search, Memoization Solution Problem Understanding The problem models a recursive elimination game played on a row of colored balls. The board is represented as a string where each character corresponds to a colored ball. The available colors are 'R' , 'Y' , 'B' , 'G' , and 'W' . You are also given another string called hand ,...

Practice › LeetCode › LeetCode 09xx ›

LeetCode 913 - Cat and Mouse

LeetCode Problem 913 Difficulty: 🔴 Hard Topics: Math, Dynamic Programming, Graph Theory, Topological Sort, Memoization, Game Theory Solution Problem Understanding In this problem, we are given an undirected graph where two players, Mouse and Cat, move alternately across the graph according to specific rules. The graph is represented as an adjacency list, where graph[a] contains all nodes directly connected to node a . The Mouse always starts at node 1...

Practice › LeetCode › LeetCode 01xx ›

LeetCode 139 - Word Break

LeetCode Problem 139 Difficulty: 🟡 Medium Topics: Array, Hash Table, String, Dynamic Programming, Trie, Memoization Solution Problem Understanding The problem asks us to determine whether a given string s can be broken into a sequence of valid words from a given dictionary wordDict . Essentially, we need to check if we can insert spaces into s such that every substring separated by these spaces exists in the dictionary. The input...

Practice › LeetCode › LeetCode 08xx ›

LeetCode 894 - All Possible Full Binary Trees

LeetCode Problem 894 Difficulty: 🟡 Medium Topics: Dynamic Programming, Tree, Recursion, Memoization, Binary Tree Solution Problem Understanding The problem asks us to generate every possible full binary tree that contains exactly n nodes. A full binary tree is a special kind of binary tree where every node has either exactly two children or no children at all. In other words, a node can never have only one child. The input...

Practice › LeetCode › LeetCode 03xx ›

LeetCode 329 - Longest Increasing Path in a Matrix

LeetCode Problem 329 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Depth-First Search, Breadth-First Search, Graph Theory, Topological Sort, Memoization, Matrix Solution Problem Understanding The problem gives us a two-dimensional grid of integers called matrix . Each position in the grid contains a value, and we are asked to find the length of the longest strictly increasing path. A path starts from any cell and moves one step at a time...

Practice › LeetCode › LeetCode 18xx ›

LeetCode 1815 - Maximum Number of Groups Getting Fresh Donuts

LeetCode Problem 1815 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Bit Manipulation, Memoization, Bitmask Solution Problem Understanding This problem asks us to maximize the number of “happy” customer groups by choosing the best possible ordering of the groups. The donut shop produces donuts in batches of exactly batchSize . A fresh batch starts only when the previous batch has been completely consumed. A group is considered happy if the very...

Practice › LeetCode › LeetCode 16xx ›

LeetCode 1611 - Minimum One Bit Operations to Make Integers Zero

LeetCode Problem 1611 Difficulty: 🔴 Hard Topics: Math, Dynamic Programming, Bit Manipulation, Recursion, Memoization Solution Problem Understanding This problem asks us to transform a given integer n into 0 using a specialized set of bit-flipping operations. Each operation allows you to flip either the rightmost bit of the binary representation of n , or the i-th bit if the (i-1)-th bit is set to 1 and all lower bits (i-2...

Practice › LeetCode › LeetCode 03xx ›

LeetCode 397 - Integer Replacement

LeetCode Problem 397 Difficulty: 🟡 Medium Topics: Dynamic Programming, Greedy, Bit Manipulation, Memoization Solution LeetCode 397 - Integer Replacement Problem Understanding The problem gives us a positive integer n and asks for the minimum number of operations required to transform it into 1 . At every step, we are allowed to apply one of two rules: If the number is even, we must divide it by 2 If the number...

Practice › LeetCode › LeetCode 00xx ›

LeetCode 70 - Climbing Stairs

LeetCode Problem 70 Difficulty: 🟢 Easy Topics: Math, Dynamic Programming, Memoization Solution LeetCode 70 - Climbing Stairs Problem Understanding The problem describes a staircase with n total steps. You start at the bottom and want to reach the top. At every move, you are allowed to climb either 1 step or 2 steps. The goal is to determine how many distinct sequences of moves can take you from the bottom...

Practice › LeetCode › LeetCode 13xx ›

LeetCode 1387 - Sort Integers by The Power Value

LeetCode Problem 1387 Difficulty: 🟡 Medium Topics: Dynamic Programming, Memoization, Sorting Solution Problem Understanding This problem asks us to rank integers according to a special metric called the "power value". The power value of a number is determined by repeatedly applying the Collatz transformation rules until the number becomes 1 . The rules are: If the number is even, divide it by 2 If the number is odd, replace it...

Practice › LeetCode › LeetCode 02xx ›

LeetCode 241 - Different Ways to Add Parentheses

LeetCode Problem 241 Difficulty: 🟡 Medium Topics: Math, String, Dynamic Programming, Recursion, Memoization Solution Problem Understanding The problem gives us a mathematical expression as a string containing integers and arithmetic operators ( + , - , * ). We are asked to compute all possible results that can be obtained by inserting parentheses in every valid way. The key detail is that we are not evaluating the expression using normal...

Practice › LeetCode › LeetCode 02xx ›

LeetCode 294 - Flip Game II

LeetCode Problem 294 Difficulty: 🟡 Medium Topics: Math, Dynamic Programming, Backtracking, Memoization, Game Theory Solution Problem Understanding This problem describes a two-player impartial game played on a string consisting only of '+' and '-' characters. A valid move consists of selecting any pair of consecutive "++" characters and flipping them into "--" . The players alternate turns. If a player cannot make a valid move on their turn, they lose...

Practice › LeetCode › LeetCode 06xx ›

LeetCode 638 - Shopping Offers

LeetCode Problem 638 Difficulty: 🟡 Medium Topics: Array, Dynamic Programming, Backtracking, Bit Manipulation, Memoization, Bitmask Solution Problem Understanding This problem asks us to find the minimum cost to buy a set of items given individual prices and optional special offers. We are given three main inputs: an array price that specifies the unit price for each item, an array needs that specifies the exact number of each item we want...

Practice › LeetCode › LeetCode 04xx ›

LeetCode 464 - Can I Win

LeetCode Problem 464 Difficulty: 🟡 Medium Topics: Math, Dynamic Programming, Bit Manipulation, Memoization, Game Theory, Bitmask Solution LeetCode 464 - Can I Win Problem Understanding This problem describes a two-player turn-based game. Players take turns choosing a number from a shared pool of integers ranging from 1 to maxChoosableInteger . Once a number is chosen, it cannot be used again for the rest of the game. Each chosen number is...

Practice › LeetCode › LeetCode 07xx ›

LeetCode 773 - Sliding Puzzle

LeetCode Problem 773 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Backtracking, Breadth-First Search, Memoization, Matrix Solution Problem Understanding The Sliding Puzzle problem presents a 2 x 3 board containing five numbered tiles from 1 to 5 and a blank space represented as 0 . The goal is to transform the board into a solved configuration [[1,2,3],[4,5,0]] using the fewest number of moves, where a move consists of swapping 0 with...

Practice › LeetCode › LeetCode 06xx ›

LeetCode 691 - Stickers to Spell Word

LeetCode Problem 691 Difficulty: 🔴 Hard Topics: Array, Hash Table, String, Dynamic Programming, Backtracking, Bit Manipulation, Memoization, Bitmask Solution Let's dive deep into a detailed technical solution guide for LeetCode 691, following your formatting rules exactly. Problem Understanding The problem asks us to construct a target string using letters cut from an unlimited supply of given stickers, where each sticker is a lowercase word. You can reuse stickers multiple times...

Practice › LeetCode › LeetCode 11xx ›

LeetCode 1137 - N-th Tribonacci Number

LeetCode Problem 1137 Difficulty: 🟢 Easy Topics: Math, Dynamic Programming, Memoization Solution LeetCode 1137, N-th Tribonacci Number Problem Understanding The problem asks us to compute the n -th number in the Tribonacci sequence. The Tribonacci sequence is very similar to the Fibonacci sequence, except that instead of summing the previous two numbers, each value is formed by summing the previous three numbers. The sequence is defined as: T0 = 0...

Practice › LeetCode › LeetCode 05xx ›

LeetCode 546 - Remove Boxes

LeetCode Problem 546 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Memoization Solution LeetCode 546, Remove Boxes Problem Understanding The problem gives us an array called boxes , where each integer represents the color of a box. We may repeatedly remove groups of adjacent boxes that share the same color. If we remove a group containing k boxes, we earn k * k points. The important detail is that removing boxes...

Practice › LeetCode › LeetCode (archived) › LeetCode 09xx ›

LeetCode 964: Least Operators to Express Number

Problem Restatement We are given two integers: x target We may build expressions using only the number x and the operators: + - * / Division is real division, and standard operator precedence applies. We cannot use unary negation. So: -x is not allowed directly. We want to express target using the minimum number of operators. Return that minimum number. The official constraints are: Constraint Value 2 <= x <=...

Practice › LeetCode › LeetCode (archived) › LeetCode 08xx ›

LeetCode 894: All Possible Full Binary Trees

Problem Restatement We are given an integer n . Return a list of all possible full binary trees with exactly n nodes. A full binary tree is a binary tree where every node has either: Children count Meaning 0 Leaf node 2 Internal node No node may have exactly one child. Each node has value 0 . We only care about the tree shapes. LeetCode asks for all possible full...

Practice › LeetCode › LeetCode (archived) › LeetCode 06xx ›

LeetCode 691: Stickers to Spell Word

Problem Restatement We are given a list of sticker words and a target string. Each sticker contains lowercase English letters. We may cut letters from stickers and rearrange them to form the target. We have infinite copies of every sticker, so the same sticker type can be used more than once. Return the minimum number of stickers needed to form target . If it is impossible, return -1 . The...

Practice › LeetCode › LeetCode (archived) › LeetCode 08xx ›

LeetCode 808: Soup Servings

Problem Restatement We have two soups, A and B . Both start with n milliliters. On each turn, one of four operations is chosen with equal probability 0.25 : Operation Soup A served Soup B served 1 100 ml 0 ml 2 75 ml 25 ml 3 50 ml 50 ml 4 25 ml 75 ml If an operation asks for more soup than remains, we serve all that remains....

Practice › LeetCode › LeetCode (archived) › LeetCode 06xx ›

LeetCode 638: Shopping Offers

Problem Restatement We are given item prices, special bundle offers, and the exact number of each item we need to buy. Each item i has an individual price: price[i] Each special offer contains quantities of items plus a final bundle price: special[j] = [count_item_0, count_item_1, ..., offer_price] We can use each special offer any number of times. The goal is to pay the minimum total cost while buying exactly the...

Practice › LeetCode › LeetCode (archived) › LeetCode 07xx ›

LeetCode 756: Pyramid Transition Matrix

Problem Restatement We are given a bottom row of blocks. Each block has a color represented by one letter. We are also given a list of allowed triples. A triple has length 3 . For example: "ABC" means: A B C If two adjacent blocks are A and B , then we may place C on top of them. Starting from the given bottom row, we need to decide whether...

Practice › LeetCode › LeetCode (archived) › LeetCode 05xx ›

LeetCode 546: Remove Boxes

Problem Restatement We are given an array boxes . Each integer represents the color of one box. In one move, we can remove a continuous group of boxes with the same color. If the group has k boxes, we gain: k * k points. After removing boxes, the remaining boxes close the gap. We repeat this until no boxes remain. We need to return the maximum score possible. The official...

Practice › LeetCode › LeetCode (archived) › LeetCode 05xx ›

LeetCode 514: Freedom Trail

Problem Restatement We are given a circular ring represented by a string ring . We are also given a string key . The ring starts with ring[0] aligned at the 12:00 position. To spell each character in key , we may: Operation Cost Rotate the ring one position clockwise 1 Rotate the ring one position counterclockwise 1 Press the center button to select the current character 1 For each character...

Practice › LeetCode › LeetCode (archived) › LeetCode 08xx ›

LeetCode 851: Loud and Rich

Problem Restatement We are given n people labeled from 0 to n - 1 . Each person has: Data Meaning quiet[i] Quietness level of person i richer[j] = [a, b] Person a is richer than person b For every person x , we need to find the quietest person among all people who are at least as rich as x . This includes: Person x Everyone directly richer than x...

Practice › LeetCode › LeetCode (archived) › LeetCode 05xx ›

LeetCode 576: Out of Boundary Paths

Problem Restatement We are given an m x n grid and a ball starting at position [startRow, startColumn] . On each move, the ball can move one cell in one of four directions: up, down, left, right The ball may also move outside the grid. We can use at most maxMove moves. Return the number of different paths that move the ball out of the grid boundary. Since the answer...

Practice › LeetCode › LeetCode (archived) › LeetCode 04xx ›

LeetCode 464: Can I Win

Problem Restatement We are given two integers: maxChoosableInteger desiredTotal There are numbers from 1 to maxChoosableInteger . Two players take turns choosing one unused number. Each chosen number is added to a running total. The player who makes the running total reach or exceed desiredTotal wins. Both players play optimally. We need to return whether the first player can force a win. The official problem asks whether the first player...

Practice › LeetCode › LeetCode (archived) › LeetCode 02xx ›

LeetCode 294: Flip Game II

Problem Restatement We are given a string currentState containing only: "+" "-" Two players take turns. On each turn, a player chooses two consecutive plus signs: "++" and flips them into: "--" The player who cannot make a move loses. We start first. We need to return whether the starting player can guarantee a win. The source statement defines the game this way: players take turns flipping two consecutive "++"...

Practice › LeetCode › LeetCode (archived) › LeetCode 02xx ›

LeetCode 241: Different Ways to Add Parentheses

Problem Restatement We are given a string expression containing: Non-negative integers Operators: + - * We need to compute all possible results from adding parentheses in every valid way. The answer may contain duplicate values if different parenthesizations produce the same result. LeetCode examples include: Input: expression = "2-1-1" Output: [0,2] and: Input: expression = "2*3-4*5" Output: [-34,-14,-10,-10,10] The expression length is at most 20 . Input and Output Item...

Practice › LeetCode › LeetCode (archived) › LeetCode 01xx ›

LeetCode 140: Word Break II

Problem Restatement We are given: Name Meaning s A string without spaces wordDict A list of valid dictionary words We need to insert spaces into s so that every piece is a valid dictionary word. Return all possible valid sentences. The same dictionary word may be reused multiple times. The answer may be returned in any order. LeetCode gives constraints including 1 <= s.length <= 20 , 1 <= wordDict.length...

Practice › LeetCode › LeetCode (archived) › LeetCode 00xx ›

LeetCode 87: Scramble String

Problem Restatement We are given two strings: s1: str s2: str Both strings have the same length. We need to return whether s2 can be produced by scrambling s1 . A scramble is formed recursively: If the string length is 1 , stop. Otherwise, split the string into two non-empty parts. Either keep the two parts in the same order or swap them. Apply the same process recursively to each...

Practice › LeetCode › LeetCode (archived) › LeetCode 04xx ›

LeetCode 488: Zuma Game

Problem Restatement We are given a row of colored balls called board and some balls in our hand called hand . Each ball has one of five colors: Character Color R Red Y Yellow B Blue G Green W White On each move, we choose one ball from hand and insert it anywhere in board . After insertion, if there are three or more consecutive balls of the same color,...

Practice › LeetCode › LeetCode (archived) › LeetCode 03xx ›

LeetCode 329: Longest Increasing Path in a Matrix

Problem Restatement We are given an m x n integer matrix. Return the length of the longest strictly increasing path in the matrix. From each cell, we may move in four directions: up, down, left, right We may not move diagonally, and we may not move outside the matrix boundary. The path must be strictly increasing, so every next cell must have a larger value than the current cell. Input...

Practice › LeetCode › LeetCode (archived) › LeetCode 04xx ›

LeetCode 403: Frog Jump

Problem Restatement A frog wants to cross a river by jumping on stones. The stones are given as a sorted array: stones Each value in stones is a position on the river. The frog starts on the first stone, which is always position 0 . The first jump must be exactly 1 unit. After that, if the frog’s previous jump was k units, then the next jump must be one...

Practice › LeetCode › LeetCode (archived) › LeetCode 00xx ›

LeetCode 10: Regular Expression Matching

Problem Restatement We are given two strings: s p s is the input string. p is the pattern. The pattern supports two special characters: Pattern symbol Meaning . Matches any single character * Matches zero or more of the preceding element The match must cover the entire input string, not only part of it. This is the key rule in the problem statement. For example: s = "aa" p =...

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LeetCode 3850 - Count Sequences to K

LeetCode 3459 - Length of Longest V-Shaped Diagonal Segment

LeetCode 3040 - Maximum Number of Operations With the Same Score II

LeetCode 3154 - Find Number of Ways to Reach the K-th Stair

LeetCode 2312 - Selling Pieces of Wood

LeetCode 2318 - Number of Distinct Roll Sequences

LeetCode 2019 - The Score of Students Solving Math Expression

LeetCode 1857 - Largest Color Value in a Directed Graph

LeetCode 2876 - Count Visited Nodes in a Directed Graph

LeetCode 2920 - Maximum Points After Collecting Coins From All Nodes

LeetCode 2998 - Minimum Number of Operations to Make X and Y Equal

LeetCode 2311 - Longest Binary Subsequence Less Than or Equal to K

LeetCode 2713 - Maximum Strictly Increasing Cells in a Matrix

LeetCode 2328 - Number of Increasing Paths in a Grid

LeetCode 1900 - The Earliest and Latest Rounds Where Players Compete

LeetCode 1553 - Minimum Number of Days to Eat N Oranges

LeetCode 1444 - Number of Ways of Cutting a Pizza

LeetCode 964 - Least Operators to Express Number

LeetCode 1575 - Count All Possible Routes

LeetCode 1569 - Number of Ways to Reorder Array to Get Same BST

LeetCode 509 - Fibonacci Number

LeetCode 140 - Word Break II

LeetCode 698 - Partition to K Equal Sum Subsets

LeetCode 1728 - Cat and Mouse II

LeetCode 1659 - Maximize Grid Happiness

LeetCode 488 - Zuma Game

LeetCode 913 - Cat and Mouse

LeetCode 139 - Word Break

LeetCode 894 - All Possible Full Binary Trees

LeetCode 329 - Longest Increasing Path in a Matrix

LeetCode 1815 - Maximum Number of Groups Getting Fresh Donuts

LeetCode 1611 - Minimum One Bit Operations to Make Integers Zero

LeetCode 397 - Integer Replacement

LeetCode 70 - Climbing Stairs

LeetCode 1387 - Sort Integers by The Power Value

LeetCode 241 - Different Ways to Add Parentheses

LeetCode 294 - Flip Game II

LeetCode 638 - Shopping Offers

LeetCode 464 - Can I Win

LeetCode 773 - Sliding Puzzle

LeetCode 691 - Stickers to Spell Word

LeetCode 1137 - N-th Tribonacci Number

LeetCode 546 - Remove Boxes

LeetCode 964: Least Operators to Express Number

LeetCode 894: All Possible Full Binary Trees

LeetCode 691: Stickers to Spell Word

LeetCode 808: Soup Servings

LeetCode 638: Shopping Offers

LeetCode 756: Pyramid Transition Matrix

LeetCode 546: Remove Boxes

LeetCode 514: Freedom Trail

LeetCode 851: Loud and Rich

LeetCode 576: Out of Boundary Paths

LeetCode 464: Can I Win

LeetCode 294: Flip Game II

LeetCode 241: Different Ways to Add Parentheses

LeetCode 140: Word Break II

LeetCode 87: Scramble String

LeetCode 488: Zuma Game

LeetCode 329: Longest Increasing Path in a Matrix

LeetCode 403: Frog Jump

LeetCode 10: Regular Expression Matching