brain

The problem asks us to select a non-empty subset of integers from a given array nums such that the product of the numbers in the subset is maximized. Each number represents a student’s exam score, and the subset represents a group of students.

The problem gives us a sequence of keyboard button press events. Each event is represented as: Here: - index is the identifier of the button that was pressed. - time is the moment when the press happened.

The problem gives us an integer array nums, and we must choose two numbers x and y from the array such that they form a strong pair.

LeetCode 2536: Increment Submatrices by One (Medium)

The problem asks us to find the smallest positive integer that is a multiple of both 2 and a given positive integer n. In other words, we are looking for the least common multiple (LCM) of 2 and n. The input n is guaranteed to be between 1 and 150, which is a very small range.

We are given an array of integers and need to support two types of queries efficiently. The first type requires adding Fibonacci numbers to a contiguous subarray: for indices from l to r, we add F₁ to the element at l, F₂ to the element at l+1, up to F{r-l+1} at position r.

The problem asks us to transform one integer n into another integer m by repeatedly modifying individual digits of n. At each step, we can increase a digit that is not 9 or decrease a digit that is not 0.

The problem presents a street with n plots on each side, for a total of 2 n plots. The goal is to count the number of ways to place houses on these plots such that no two houses are adjacent on the same side of the street.

This problem gives us a binary tree that always contains exactly three nodes. There is one root node, one left child, and one right child. We must determine whether the value stored in the root node is equal to the sum of the values stored in its two children.

The problem gives us the root of a binary tree and asks us to replace every node’s value with the sum of all of its cousins’ values.

Codeforces 424C: Magic Formulas

The problem requires identifying users who verified their signup exactly on the second day after registering. We have two tables: emails and texts. The emails table contains the emailid, the userid, and the signupdate.

The problem describes how a secret spreads over time. On day 1, exactly one person knows the secret. Every person who learns the secret behaves according to two rules: 1. They must wait delay days before they can begin sharing the secret. 2.

We have n people placed on a line at strictly increasing coordinates. PMP starts at person s, which immediately counts as visited. Every later move must go either strictly left or strictly right, depending on the ticket used for that move.

The problem gives us a compressed string where every character is immediately followed by its frequency. For example, the string "a3b2" represents the original expanded string "aaabb". However, the input compression is not guaranteed to be optimal.

The problem gives us a database table named cities, where each row contains a state name and a city name. The pair (state, city) is guaranteed to be unique, which means the same city will not appear twice for the same state. We must generate a report for qualifying states.

We are given two integers, s and k. The task is to express s as a sum of distinct numbers taken from the k-bonacci sequence. The sequence behaves like Fibonacci, but instead of summing the previous two values, each term is the sum of the previous k terms.

Codeforces 263B: Squares

The problem asks us to process a set of suffix matching queries efficiently. We are given two arrays: - wordsContainer, which contains candidate strings - wordsQuery, which contains query strings For every query string, we must find the index of the string in wordsContainer…

This problem takes place on a two-dimensional grid where each cell represents a type of terrain. The grid contains: - "S": your starting position. - "D": the destination you want to reach. - ".": an empty cell that can be walked on. - "X": a stone cell that cannot be entered.

The problem asks us to count the number of special permutations of a given array of distinct positive integers nums.

The problem asks us to compute a Premier League-style ranking table from a TeamStats table, which contains each team's matches played, wins, draws, and losses. We are required to calculate three additional columns for each team: points, position, and tier.

This problem asks us to determine if a given object or array is empty. In JavaScript terms, an object is empty if it has no key-value pairs, while an array is empty if it has no elements.

We are given a directed acyclic graph with vertices numbered from 1 to n, where every edge goes from a smaller-numbered vertex to a larger-numbered vertex. Some edges already exist, and we are allowed to add more edges under certain constraints.

We process a sequence of tiles, each tile being either 2 or 4. A tile starts far to the right and slides left. When it touches an equal value, the two merge into a doubled value and the new tile keeps moving.

You are given an array heights, where each index represents a building and the value represents that building's height.

This problem asks us to multiply two arrays that are already stored in run-length encoded form, without fully expanding them into normal arrays. A run-length encoded array stores consecutive repeated values compactly.

The problem gives us the root of a binary tree, where every node contains a positive integer value. Our task is to determine which level of the tree has the smallest sum of node values.

We are given a polyline representing mountain peaks. The polyline has 2n + 1 vertices, with even-indexed vertices (2, 4, 6, ..., 2n) representing peaks. In the initial picture, each peak is strictly higher than its neighbors, i.e., for every even i, y[i-1] < y[i] y[i+1].

The problem describes a street represented by positions from 0 to n - 1. There are multiple street lamps, each defined by its position and range. A lamp at position p with range r illuminates all positions from max(0, p - r) to min(n - 1, p + r), inclusive.

We are given an array of positive integers and a set of "bad" prime numbers. Every other prime not in the bad set is implicitly "good." Each number in the array contributes to a total "beauty" score determined by its prime factorization.

The problem asks us to determine the minimum number of characters to take from either end of a string s consisting only of the letters 'a', 'b', and 'c' so that we collect at least k of each character.

The problem asks us to analyze a given string word where each lowercase English letter is mapped to a digit according to a classic phone keypad scheme.

We are given a string s representing Alice’s moves across n rounds of a game. Each character corresponds to one creature: - 'F' = Fire Dragon - 'W' = Water Serpent - 'E' = Earth Golem In every round, Alice and Bob each choose one creature simultaneously.

The problem asks us to partition a given binary string s into the minimum number of substrings such that each substring is beautiful. A substring is beautiful if it represents a power of 5 in decimal and does not have leading zeros.

We are asked to determine whether a robot, which can only make fence corners at a fixed angle a, can construct a regular polygon. A regular polygon is defined as a closed shape with all sides and all angles equal.

We have an array of friend attractiveness values. Every unordered pair of distinct friends produces one possible picture, and the value of that picture is the xor of the two attractiveness values.

This problem asks us to take a string of lowercase English letters and convert it into a numeric value, then repeatedly transform that number by summing its digits.

The problem gives us an array called colors of length n. Initially, every element is 0, which represents an uncolored position. We then process a sequence of queries.

This problem asks us to implement a custom version of setInterval, but with a key difference. Instead of using a fixed delay between executions, the delay grows linearly according to the formula: where count starts at 0 and increases after every execution.

The motion takes place on two adjacent faces of the cube.

The problem asks for the locus of the centroid of a triangle whose vertices are the midpoints of three segments joining fixed points above a plane to arbitrary points on the plane.

The geometry becomes transparent after reducing the three-dimensional configuration to a two-dimensional meridian section through the axis of the cone.

The problem asks for two loci inside a cube.

We are asked to analyze functions $f:\mathbb{Q} \to \mathbb{Q}$ satisfying the following property: for every $x,y \in \mathbb{Q}$, at least one of the two identities

The board has $2024$ rows and $2023$ columns.

We must prove

For each $n>N$, the sequence satisfies

For each real number $\alpha$, define

The problem gives a list of online courses, where each course is represented as [duration, lastDay]. The duration tells us how many consecutive days are required to complete the course. The lastDay tells us the latest possible day by which the course must be finished.

This problem asks us to identify the project or projects that have the largest number of employees assigned to them. We are given two database tables. The Project table stores relationships between projects and employees.

The problem gives us an integer array nums and a collection of range requests. Each request [start, end] asks for the su

The input is a numeric string num that is guaranteed to already be a palindrome. The task is to rearrange its digits to create another palindrome that is strictly larger than the original number, while also being the smallest such palindrome possible.

The problem asks us to determine the minimum number of moves required to identify a critical floor in a building using a limited number of eggs.

The problem can be restated as simulating bullets flying along the positive _Z_ axis at given coordinates on a 2D shooting plane (_XOY_). Each bullet may hit one of multiple rectangular targets floating at distinct heights along the _Z_ axis.

The problem gives an integer array nums and asks whether any number appears more than once. If at least one value is repeated, we return true. If every value appears exactly once, we return false. The input is a list of integers.

The problem gives us an integer array nums and a maximum jump distance k. We start at index 0, and from any position i,

The problem asks us to determine whether two binary expression trees are equivalent, where equivalence is defined as the trees representing the same arithmetic expression, modulo the order of addition since addition is commutative.

This is a SQL database problem where we need to identify the employees who belong to the top three unique salaries within each department.

We are asked to start with the number pair (1,1) and reach a pair where at least one of the numbers equals a given target n. At each step, we can add one number to the other to form a new pair. Concretely, if our current pair is (a, b), the next pair can be (a+b, b) or (a, a+b).

The problem asks us to rearrange the characters of a string so that characters with higher frequency appear before characters with lower frequency. The output string must group identical characters together, and those groups must appear in descending order of occurrence count.

The problem asks us to find the length of the longest string in the array that is not a subsequence of any other string in the same array. A subsequence is formed by deleting zero or more characters from a string without changing the order of the remaining characters.

This problem asks us to maximize the number of children who can be satisfied with the available cookies. Each child has a greed factor, and each cookie has a size. A child becomes content only if they receive a cookie whose size is greater than or equal to their greed factor.

In this problem, we are given a list of travel days during a single year and the costs of three different train passes. Each pass covers a consecutive range of days: - A 1-day pass covers exactly one day. - A 7-day pass covers seven consecutive days.

This problem asks us to determine whether one binary tree appears as an exact subtree inside another binary tree.

The problem gives us a binary string s, meaning the string contains only the characters '0' and '1'. We must split this string into two non-empty parts, a left substring and a right substring.

This problem asks us to determine the weather type for each country during November 2019, based on the average weatherst

The problem provides a database table named Employee that stores information about which departments employees belong to.

The problem gives us two water jugs with capacities x and y. We can perform only three types of operations: - Fill a jug completely - Empty a jug completely - Pour water from one jug into the other until either the source jug becomes empty or the destination jug becomes full…

We have two arrays representing the order of students in a line. Array a is the desired arrangement, and array b is the current arrangement. In one operation we may swap two neighboring students. We must output any sequence of adjacent swaps that transforms b into a.

The problem asks us to compute the ordinal day number of a year given a date in the format YYYY-MM-DD. For example, January 1st is always day 1, January 2nd is day 2, and December 31st is either day 365 or 366 depending on whether the year is a leap year.

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.

The problem asks us to determine whether a given integer becomes a different valid number after being rotated by 180 degrees. Not every digit remains valid after rotation.

We are asked to construct a fully connected graph of _N_ tourist attractions, where each road has a distinct positive integer cost not exceeding 1000.

The problem gives us two sorted integer arrays, nums1 and nums2, and asks us to return the k pairs with the smallest sums. A pair is formed by taking one element from nums1 and one element from nums2.

The problem gives us a binary array called flowerbed, where: - 0 represents an empty plot - 1 represents a plot that already contains a flower We are also given an integer n, which represents how many new flowers we want to plant.

The problem is asking us to design a system that tracks tweets by their timestamp and allows querying the number of tweets in specific time intervals, split according to a frequency (minute, hour, or day).

We have a rectangular grid. Each cell contains either a terrain type represented by a lowercase letter, the start cell S, or the target cell T. We may move in four directions between side-adjacent cells. Every move costs exactly one minute. The path must start at S and end at T.

We are given a tree of n cities, meaning each city is connected in such a way that there is exactly one simple path between any two cities. Roads are undirected, and each road has a length of 1.

The problem asks us to evaluate a Lisp-like expression represented as a string. The expression can contain integers, variables, and three special operations: let, add, and mult. An expression evaluates to a single integer value.

The problem describes a classic interactive guessing game. A hidden number called pick is chosen somewhere in the range from 1 to n, inclusive. We are not allowed to access pick directly.

The problem asks us to count how many permutations of the numbers 1 through n are valid derangements. A derangement is a permutation where no element remains in its original position. For example, when n = 3, the original array is [1, 2, 3].

The problem requires classifying triangles based on the lengths of their three sides, represented by the columns A, B, a

The problem gives us two inputs: an array of strings called words, and a target string s. Every occurrence of every word from words inside s must become bold by surrounding that substring with <b and </b tags.

We are given an encrypted password represented as a binary string of length 80. The original password had exactly 8 decimal digits, and each digit was encoded into a block of 10 binary characters.

The problem gives us the head of a singly linked list and an integer k. We must divide the linked list into exactly k consecutive parts while preserving the original order of nodes. The important requirement is that the parts should be as evenly sized as possible.

You asked for the complete guide in a single response, but your previous message includes two separate LeetCode problems

We have a complete binary tree of height h. Every vertex may store some number of electrons, and queries gradually add more electrons to vertices. A decay operation chooses one leaf uniformly at random and deletes every edge on the path from the root to that leaf.

The problem asks us to find the kth factor of a positive integer n, where the factors are ordered in ascending order. A

The problem asks us to compute the sum of the minimum value of every possible contiguous subarray of a given array. For an array arr, every contiguous slice of the array is considered a subarray. For each subarray, we determine its minimum element.

This problem asks us to compute, for every node in a rooted tree, the smallest positive integer that does not appear in the subtree rooted at that node. We are given two arrays: parents describes the tree structure, and nums contains distinct genetic values assigned to each node.

We are asked to prepare a set of additional undirected edges, called wormholes, on top of an unknown tunnel system.

The problem gives us a string called text and a list of dictionary words called words. We must find every substring inside text that exactly matches one of the words in the dictionary.

The problem requires rearranging spaces in a given string text so that all words are separated by the maximum possible e

This problem asks us to traverse a binary tree and identify every node that is considered "lonely". A node is lonely if

You are given several bags of balls, where nums[i] represents how many balls are inside the i-th bag. You are allowed to perform at most maxOperations split operations.

The bank stores diamonds in a row of cells. After every minute, the security system checks the sums of every adjacent pair: $$a1 + a2, a2 + a3, dots, a{n-1} + an$$ If any of these sums changes compared to the previous check, the alarm triggers.

The problem asks us to determine the maximum number of candies we can collect from a set of boxes with varying accessibi

The problem is asking us to find the next greater element for each element in nums1 within another array nums2. Formally, for each element in nums1, we need to locate its position in nums2 and then find the first element to its right in nums2 that is greater than itself.

The problem gives us a binary number represented as a string s. Our task is to determine how many operations are require