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Remove all elements from a linked list of integers that have value val.ExampleGiven: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6,  val = 6Return: 1 --> 2 --> 3 --> 4 --> 5Credits:Special thank

Given the root of a tree, you are asked to find the most frequent subtree sum. The subtree sum of a node is defined as the sum of all the node values formed by the subtree rooted at that node (includi

You need to find the largest value in each row of a binary tree.Example:Input: 1 / \ 3 2 / \ \ 5 3 9 Output: [1, 3, 9]Subsc

Given a string, sort it in decreasing order based on the frequency of characters.Example 1:Input:"tree"Output:"eert"Explanation:'e' appears twice while 'r' and 't' both appear once.So 'e

Given n points in the plane that are all pairwise distinct, a "boomerang" is a tuple of points (i, j, k) such that the distance between iand j equals the distance between i and k (the order of t

Given a string s and a non-empty string p, find all the start indices of p's anagrams in s.Strings consists of lowercase English letters only and the length of both strings s and p will not be lar

Given an array of integers with possible duplicates, randomly output the index of a given target number. You can assume that the given target number must exist in the array.Note:The array size c

Given a n x n matrix where each of the rows and columns are sorted in ascending order, find the kth smallest element in the matrix.Note that it is the kth smallest element in the sorted order, not t

Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set.get(key) - Get the value (will always be positive) of the key if

Given inorder and postorder traversal of a tree, construct the binary tree.Note:You may assume that duplicates do not exist in the tree.Subscribe to see which companies asked this

Given preorder and inorder traversal of a tree, construct the binary tree.Note:You may assume that duplicates do not exist in the tree.Subscribe to see which companies asked this q

Median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value. So the median is the mean of the two middle value.Examples: [2,3,4] , the me

Given a non-empty array of integers, return the k most frequent elements.For example,Given [1,1,1,2,2,3] and k = 2, return [1,2].Note: You may assume k is always valid, 1 ≤ k ≤ number

Given a nested list of integers, implement an iterator to flatten it.Each element is either an integer, or a list -- whose elements may also be integers or other lists.Example 1:Given the list [

Implement a trie with insert, search, and startsWith methods.Note:You may assume that all inputs are consist of lowercase letters a-z.Subscribe to see which companies asked this

Given an array of strings, group anagrams together.For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"], Return:[  ["ate", "eat","tea"],  ["nat","tan"],  ["bat"]]Note:

Given an array of integers, return indices of the two numbers such that they add up to a specific target.You may assume that each input would have exactly one solution.Example:Given nums =

You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a link

Given a binary tree, return the zigzag level order traversal of its nodes' values. (ie, from left to right, then right to left for the next level and alternate between).For example:Given binary