Do not mess it up

You are given a stringsand two integersxandy. You can perform two types of operations any number of times.Remove substring"ab"and gainxpoints. For example, when removing"ab"from"cabxbae"it becomes"cxbae". Remove substring"ba"and gain...

Given an array ofintegersarr.We want to select three indicesi,jandkwhere(0 <= i < j <= k < arr.length).Let's defineaandbas follows:a = arr[i] ^ arr[i + 1] ^ ... ^ arr[j - 1] b = arr[j] ^ arr[j + 1] ^ ... ^ arr[k]Note that^...

Given a list of lists of integers,nums,return all elements ofnumsin diagonal order as shown in the below images.Example 1:Input: nums = [[1,2,3],[4,5,6],[7,8,9]]Output: [1,4,2,7,5,3,...

Given the stringcroakOfFrogs, which represents a combination of the string "croak" from different frogs, that is, multiple frogs can croak at the same time, so multiple “croak” are mixed.Return the ...

Ahappy stringis a string that:consists only of letters of the set['a', 'b', 'c']. s[i] != s[i + 1]for all values ofifrom1tos.length - 1(string is 1-indexed).For example, strings"abc", "...

Given the numberk,return the minimum number of Fibonacci numbers whose sum is equal tok, whether a Fibonacci number could be used multiple times.The Fibonacci numbers are defined as:F1= 1 F2...

Given a numbersin their binary representation. Return the number of steps to reduce it to 1 under the following rules: If the current number is even, you have to divide it by 2. If the curre...

Aninteger hassequential digitsif and only if each digit in the number is one more than the previous digit.Return asortedlist of all the integersin the range[low, high]inclusive that have seq...

There arencities numbered from0ton-1. Given the arrayedgeswhereedges[i] = [fromi, toi, weighti]represents a bidirectional and weighted edge between citiesfromiandtoi, and given the integer...

Given the arrayarrof positive integers and the arrayquerieswherequeries[i] = [Li,Ri],for each queryicompute theXORof elements fromLitoRi(that is,arr[Li]xorarr[Li+1]xor...xorarr[R...

Given an equation, represented bywordson left side and theresulton right side.You need to check if the equation is solvableunder the following rules:Each character is decoded as one digit (0 ...

Given an arraynumsofpositive integers. Your task is to select some subset ofnums, multiply each element by an integer and add all these numbers.The array is said to begoodif you can obtain a su...

Given an array of integersnumsand an integerk. Asubarrayis calledniceif there arekodd numbers on it.Return the number ofnicesub-arrays.Example 1:Input: nums = [1,1,2,1,1], k = 3O...

You are given two stringss1ands2of equal lengthconsisting of letters"x"and"y"only. Your task is tomake these two strings equal to each other. You can swap any two characters that belong tod...

Given 2 integersnandstart. Your task is returnanypermutationpof(0,1,2.....,2^n -1)such that :p[0] = start p[i]andp[i+1]differ by only one bit in their binary representation. p[0]andp...

Given an arraynumsof positive integers, return the longest possible length of an array prefix ofnums, such that it is possible to removeexactly oneelement from this prefix so that every number th...

Given two integers A and B, return any string S such that:S has length A + B and contains exactly A 'a' letters, and exactly B 'b' letters; The substring 'aaa' does not occur in S; The substring '...

For stringsSandT, we say "TdividesS" if and only ifS = T + ... + T (Tconcatenated with itself 1 or more times)Return the largest stringXsuch thatXdividesstr1andXdividesstr2.Exa...

Given an arrayAof positive integers (not necessarily distinct), return the lexicographically largest permutation that is smaller thanA, that can bemade with one swap(Aswapexchanges the position...

You haveNgardens, labelled1toN. In each garden, you want to plant one of 4 types of flowers.paths[i] = [x, y]describes the existence of a bidirectional path from gardenxto gardeny.Also, ...

On an infinite plane, arobot initially stands at(0, 0)and faces north.The robot can receive one of three instructions:"G": go straight 1 unit; "L": turn 90 degrees to the left; "R": turn 90 d...

In a 1 million by 1 million grid, the coordinates of each grid square are(x, y)with0 <= x, y < 10^6.We start at thesourcesquare and want to reach thetargetsquare. Each move, we can wal...

Given an array A of positive lengths, return the largest perimeter of a triangle with non-zero area, formed from 3 of these lengths.If it is impossible to form any triangle of non-zero area, return ...

Alice and Bob take turns playing a game, with Alice starting first.Initially, there is a numberNon the chalkboard. On each player's turn, that player makes amoveconsisting of:Choosinganyxw...

Given a numberN, return a string consisting of"0"s and"1"sthat represents its value in base-2(negative two).The returned string must have no leading zeroes, unless the string is"0".Examp...

Given a positive integerK, you need find thesmallestpositive integerNsuch thatNis divisible byK, andNonly contains the digit1.Return thelength ofN. If there is no suchN,return -1....

On a N x N grid of cells, each cell (x, y) with 0 &lt;= x &lt; N and 0 &lt;= y &lt; N has a lamp.Initially, some number of lamps are on.  lamps[i] tells us the location of the i-th lamp that is on. ...

In an array A containing only 0s and 1s, a K-bit flip consists of choosing a (contiguous) subarray of length K and simultaneously changing every 0 in the subarray to 1, and every 1 in the subarray to ...

On a broken calculator that has a number showing on its display, we can perform two operations:Double: Multiply the number on the display by 2, or; Decrement: Subtract 1 from the number on the disp...

Given amatrixconsisting of 0s and 1s, we may choose any number of columns in the matrix and flipeverycell in that column. Flipping a cell changes the value of that cell from 0 to 1 or from 1 to 0...

Given two numbersarr1andarr2in base-2, return the result of adding them together.Each number is given inarray format: as an array of 0s and 1s, from most significant bit to least significant ...

Given amatrix, and atarget, return the number of non-empty submatrices that sum totarget.A submatrixx1, y1, x2, y2is the set of all cellsmatrix[x][y]withx1 <= x <= x2andy1 <= y &l...

Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist. Assume that there is only one duplicate number, fi...

Write a program to find then-th ugly number.Ugly numbers arepositive integerswhich are divisible byaorborc.Example 1:Input: n = 3, a = 2, b = 3, c = 5Output: 4Explanation: The ugly...

Given an integer arrayarrand an integerk, modify the array by repeating itktimes.For example, ifarr= [1, 2]andk = 3then the modified array will be[1, 2, 1, 2, 1, 2].Return the maximum s...

Given an array of integers, return the maximum sum for anon-emptysubarray (contiguous elements) with at most one element deletion.In other words, you want to choose a subarray and optionally delete...

With respect to a givenpuzzlestring, awordisvalidif both the following conditions are satisfied:wordcontains the first letter ofpuzzle. For each letter inword, that letter is inpuzzle. F...

Implementing the classMajorityChecker, which has the following API:MajorityChecker(int[] arr)constructs an instance of MajorityChecker with the given arrayarr; int query(int left, int right, int...

Alexand Lee continue theirgames with piles of stones. There are a number ofpilesarranged in a row, and each pile has a positive integer number of stonespiles[i]. The objective of the game is to...

Given two arrays of integers with equal lengths, return the maximum value of:|arr1[i] - arr1[j]| + |arr2[i] - arr2[j]| + |i - j|where the maximum is taken over all0 <= i, j < arr1.length....