Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any order.

Given a sorted array, find the k closest integers to x. The result should also be sorted in ascending order.

Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. If target is not found, return [-1, -1].

You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you is that adjacent houses have security systems connected and it will automatically contact the police if two adjacent houses were broken into on the same night.

Given an integer array nums, find a subarray that has the largest product, and return the product.

Given n nodes labeled from 0 to n - 1 and a list of undirected edges, write a function to check whether these edges make up a valid tree.

Given an integer array nums, find the subarray with the largest sum, and return its sum.

Given an array of points where points[i] = [xi, yi] represents a point on the X-Y plane and an integer k, return the k closest points to the origin (0, 0). The distance between two points is the Euclidean distance. You may return the answer in any order.

Given an integer array nums and an integer k, return the kth largest element in the array. Note that it is the kth largest element in the sorted order, not the kth distinct element.

Given two sorted arrays nums1 and nums2, find k pairs (u1, v1), (u2, v2), ..., (uk, vk) with the smallest sums.

You are given an array of non-overlapping intervals intervals where intervals[i] = [starti, endi] represent the start and the end of the ith interval and intervals is sorted in ascending order by starti. You are also given an interval newInterval = [start, end] that represents the start and end of another interval. Insert newInterval into intervals such that intervals is still sorted in ascending order by starti and intervals still does not have any overlapping intervals (merge overlapping intervals if necessary).

You are given an array of k linked-lists lists, each linked-list is sorted in ascending order. Merge all the linked-lists into one sorted linked-list and return it.

Implement pow(x, n), which calculates x raised to the power n (i.e., x^n). Use the fast exponentiation algorithm to achieve O(log n) time complexity.

Given two strings s and t of lengths m and n respectively, return the minimum window substring of s such that every character in t (including duplicates) is included in the window. If there is no such substring, return the empty string "".

Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are +, -, *, and /. Each operand may be an integer or another expression. Note that division between two integers should truncate toward zero.

Given two strings s and t, determine if they are isomorphic. Two strings are isomorphic if the characters in s can be replaced to get t.

Given an array of words and a maxWidth, format the text such that each line has exactly maxWidth characters and is fully (left and right) justified.

Given the root of a binary tree, return its maximum depth.

Given a binary search tree (BST), find the lowest common ancestor (LCA) node of two given nodes in the BST.

Find the lowest common ancestor (LCA) of two nodes in a binary tree. The LCA is the lowest node that has both p and q as descendants.

Given the root of a binary tree, return the level order traversal of its nodes' values. (i.e., from left to right, level by level).

Design an algorithm to serialize and deserialize a binary tree. There is no restriction on how your serialization/deserialization algorithm should work.

Given the root of a binary tree, return the zigzag level order traversal of its nodes values. (i.e., from left to right, then right to left for the next level and alternate between).

Implement the BSTIterator class that represents an iterator over the in-order traversal of a binary search tree (BST). The class should have a constructor that takes the root of a BST, a next() method that returns the next smallest number, and a hasNext() method that returns whether there is a next number.