Implement a first in first out (FIFO) queue using only two stacks. The implemented queue should support all the functions of a normal queue (push, peek, pop, and empty). Implement the MyQueue class:vo

Design a data structure that follows the constraints of a Least Recently Used (LRU) cache. Implement the LRUCache class: LRUCache(int capacity) Initialize the LRU cache with positive size capacity. i

Given an integer array nums sorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order. Example 1:Input: nums = [-4,-1,0,3,10]Output: [0,1,9,16,1

Given an m x n matrix mat, return an array of all the elements of the array in a diagonal order. Example 1:Input: mat = [[1,2,3],[4,5,6],[7,8,9]]Output: [1,2,4,7,5,3,6,8,9] Example 2:Input: mat &

Design a stack that supports push, pop, top, and retrieving the minimum element in constant time. Implement the MinStack class: MinStack() initializes the stack object.void push(int val) pushes the el

Given an m x n integer matrix matrix, if an element is 0, set its entire row and column to 0’s. You must do it in place. Example 1:Input: matrix = [[1,1,1],[1,0,1],[1,1,1]]Output: [[1,0,1],[0,0,0

Given a positive integer n, generate an n x n matrix filled with elements from 1 to n2 in spiral order. Example 1:Input: n = 3Output: [[1,2,3],[8,9,4],[7,6,5]] Example 2:Input: n = 1Output:

Given an m x n matrix, return all elements of the matrix in spiral order. Example 1:Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]Output: [1,2,3,6,9,8,7,4,5] Example 2:Input: matrix = [[1,2,3,4],

You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise). You have to rotate the image in-place, which means you have to modify the input 2D matrix directly.

There are n gas stations along a circular route, where the amount of gas at the ith station is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from the ith stat