order and str are strings composed of lowercase letters. In order, no letter occurs more than once. order was sorted in some custom order previously. We want to permute the characters of str so that t

Given two n x n binary matrices mat and target, return true if it is possible to make mat equal to target by rotating mat in 90-degree increments, or false otherwise. Example 1: Input: mat = [[0,

Given an array of integers arr, replace each element with its rank. The rank represents how large the element is. The rank has the following rules: Rank is an integer starting from 1. The larger the

You are given an integer array heights representing the heights of buildings, some bricks, and some ladders. You start your journey from building 0 and move to the next building by possibly using bric

Design a system that manages the reservation state of n seats that are numbered from 1 to n. Implement the SeatManager class: SeatManager(int n) Initializes a SeatManager object that will manage n se

Design a Leaderboard class, which has 3 functions: addScore(playerId, score): Update the leaderboard by adding score to the given player’s score. If there is no player with such id in the leaderboard,

The frequency of an element is the number of times it occurs in an array. You are given an integer array nums and an integer k. In one operation, you can choose an index of nums and increment the elem

Design a queue that supports push and pop operations in the front, middle, and back. Implement the FrontMiddleBack class:FrontMiddleBack() Initializes the queue.void pushFront(int val) Adds val to the

You are given a string s of even length. Split this string into two halves of equal lengths, and let a be the first half and b be the second half. Two strings are alike if they have the same number of

You are given a 2D integer array orders, where each orders[i] = [price, amount, orderType] denotes that amount orders have been placed of type orderType at the price price. The orderTyp is:0 if i