1) Given an integer array nums and two integers left and right, return the number of contiguous non-empty subarrays such that the value of the maximum array element in that subarray is in the range [left, right]. 2) Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.

1) Given an integer, is the 180 degree rotation of it equal to the original integer? 2) Given a list of Product Id pairs, group them according to their categories and return the new list containing categorized Product Ids.

1) Given a vertex and a list of points and an integer k, return the k closest points to the vertex. 2) Modify this solution to work with an infinite stream of points instead of a list.

1) Given an absolute path containing `.` for the current directory and `..` for the parent directory, evaluate the file path such that it is in its final absolute form. 2) Given two numbers as strings, return their sum as a string.

1) Reverse the signed integer. 2) Find all triplets in an array that sum to zero.

Given an array representing a parking lot, find the closest euclidean distance spot to each car, avoiding walls.

Given an array of integers, sort the list by spawning new threads and sleeping for the amount specified by the integer.

Given a list of numbers and a target, return the pair of indices whose values in the contiguous subarray from the first index of the pair to the second index of the pair sum to the target value.

1) Given a 2D array of true and false, determine the height of the highest peak where true represents water and false represents land. The largest transition between land heights can be at most 1. 2) Determine the highest peak and optimize for the most beaches. A beach is any land with a height of 0.

Print out all numbers in binary, preserving leading zeros.

Design a max heap.

1) Find the K closest points to a vertex 2) How would you modify the solution if the input was an infinite streak of points?

1) Find the most frequent integer in an array 2) Print out pairs of numbers in an array that sum to N 3) Find the only integer that only appears once in an array in constant space and O(n) time

Given an input string (s) and a pattern (p), implement regular expression matching with support for '.' and '*'. '.' Matches any single character. '*' Matches zero or more of the preceding element. The matching should cover the entire input string (not partial).

1) Debug this piece of code. 2) We want to delete certain nodes from a binary tree. We have a function `shouldDelete(TreeNode node)` that returns true if we should delete that node, you can assume this function already exists. Write a function `deleteNodes(TreeNode root)` that takes a binary tree which removes the nodes that should be deleted from the tree and returns a forest of trees.

Given an input string (s) and a pattern (p), implement regular expression matching with support for '.' and '*'. '.' Matches any single character. '*' Matches zero or more of the preceding element. The matching should cover the entire input string (not partial).

Given a binary search tree with two flipped values, recover the BST without altering its structure

Given a Set of numbers, find and return the 3rd smallest number

Given a string with multiple words and spaces represented as a character array. Write an in-place algorithm to reverse the order of words in the string. Example: convert ['p', 'e', 'r', 'f', 'e', 'c', 't', ' ', 'm', 'a', 'k', 'e', 's', ' ', 'p', 'r', 'a', 'c', 't', 'i', 'c', 'e'] to ['p', 'r', 'a', 'c', 't', 'i', 'c', 'e', ' ', 'm', 'a', 'k', 'e', 's', ' ', 'p', 'e', 'r', 'f', 'e', 'c', 't']

Given an unsorted array, find the nth smallest element in the array