Python

Given the head of a linked list, return the list after sorting it in ascending order.

A trie(prefix tree) is a tree data structure used to efficiently store and retrieve keys in a dataset of strings. Implement the Trie class.

Given an integer array nums and an integer k, return the kth largest element in the array.

Given two integer arrays preorder and inorder where preorder is the preorder traversal of a binary tree and inorder is the inorder traversal of the same tree, construct and return the binary tree.

Given the root of a Binary Search Tree (BST), return the minimum difference between the values of any two different nodes in the tree.

Given the root of a Binary Search Tree (BST), convert it to a Greater Sum Tree

Given the root of a Binary Search Tree (BST), convert it to a Greater Sum Tree

Given an integer array nums where the elements are sorted in ascending order, convert it to a height-balanced binary search tree.

Given a tree of n nodes, return a list of all MHT(Minimum Height Tree)s' root labels.'

Given a binary tree, determine if it is height-balanced.

Design an algorithm to serialize and deserialize a binary tree.

You are given two binary trees root1 and root2. Return the merged tree.

Given the root of a binary tree, invert the tree, and return its root.

Given the root of a binary tree, return the length of the longest path, where each node in the path has the same value.

Given the root of a binary tree, return the length of the diameter of the tree.

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

Given an integer array nums of unique elements, return all possible cheapest Flights within k Stops (the power set). The solution set must not contain duplicate cheapest Flights within k Stops. Return the solution in any order.

Given an integer array nums of unique elements, return all possible network Delay Time (the power set). The solution set must not contain duplicate network Delay Time. Return the solution in any order.

Given an integer array nums of unique elements, return all possible course Schedule (the power set). The solution set must not contain duplicate course Schedule. Return the solution in any order.

Given an integer array nums of unique elements, return all possible reconstruct Itinerary (the power set). The solution set must not contain duplicate reconstruct Itinerary. Return the solution in any order.

Given an integer array nums of unique elements, return all possible subsets (the power set). The solution set must not contain duplicate subsets. Return the solution in any order.

Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target.

Given two integers n and k, return all possible combinations of k numbers chosen from the range [1, n]. You may return the answer in any order.

Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent

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

Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.

Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.

Given a string s, find the length of the longest substring without repeating characters.

Design a HashMap without using any built-in hash table libraries.

Merge multiple linked lists, each of which is sorted in ascending order

How many more days do we have to wait for the temperatures to be higher?

Given a string `s`, remove duplicate letters so that every letter appears once and only once.

Given a string `s` containing just the characters `(`, `)`, `{`, `}`, `[` and `]`, determine if the input string is valid.

Given the head of a singly linked list, group all the nodes with odd indices together followed by the nodes with even indices, and return the reordered list.

Given the head of a singly linked list and two integers left and right where left <= right, reverse the nodes of the list from position left to position right, and return the reversed list.

Given two linked lists, add two linked lists in node-wise and return the resulting list

Swap every pair of the linked list. You are not supposed to change the value of the node.

Given the head of a singly linked list, reverse the list, and return the reversed list.

Given a two sorted linked list, merge these into a new linked list.

Given a list of integers, return a new list where each element is the product of all elements in the original list except for the element at the same index.

Given a linked list, determine whether it forms a palindrome.

Given a list of integers, return a new list where each element is the product of all elements in the original list except for the element at the same index.

Find the maximum sum of pairs (a, b) where the minimum of (a, b) is maximized.

When given an array of integers, find three elements that sum up to zero.

This problem involves finding the total volume of water trapped between walls in a given landscape. Solve this!

Find two element index where sum of two elements equals to the target

Identify the longest substring that forms a palindrome

An anagram is a word or phrase formed by rearranging the letters of another word or phrase, using all the original letters exactly once. Group these!

You are given a list of logs. Re-order this for your teammates to analyze!

You are given a string and a list of banned words. Find the most frequent word in the list except for the words that are in the banned list.

Palindrome is a string that maintains its original spelling when read both forwards and backwards. Find the algorithm that detects one!

Palindrome is a string that maintains its original spelling when read both forwards and backwards. Find the algorithm that detects one!