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Given a sorted array nums, remove the duplicates in-place such that each element appears only once and returns the new length.Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.Cla

Given an integer n, return the number of trailing zeroes in n!.Example 1:Input: 3Output: 0Explanation: 3! = 6, no trailing zero.Example 2:Input: 5Output: 1Explanation: 5! = 120, one trailing zero.public class Solution { public int trailin

Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.(i.e., [0,1,2,4,5,6,7] might become [4,5,6,7,0,1,2]).Find the minimum element.You may assume no duplicate exists in the array.Example 1:Input: [3,4,5,1,2]

Given an array of integers arr, replace each element with its rank.The rank represents how large the element is. The rank has the following rules:Rank is an integer starting from 1.The larger the e...

You are given an array of strings words and a string chars.A string is good if it can be formed by characters from chars (each character can only be used once).Return the sum of lengths of all good ...

const _max = Math.max.bind(Math);const _min = Math.min.bind(Math);const _pow = Math.pow.bind(Math);const _floor = Math.floor.bind(Math);const _round = Math.round.bind(Math);const _ceil = Math.cei...

We are given two sentences A and B. (A sentence is a string of space separated words. Each word consists only of lowercase letters.)A word is uncommon if it appears exactly once in one of the sente...

Given n points on a 2D plane, find the maximum number of points that lie on the same straight line.Example 1:Input: [[1,1],[2,2],[3,3]]Output: 3Explanation:^|| o| o| o +--------...

Implement the following operations of a queue using stacks.push(x) – Push element x to the back of queue.pop() – Removes the element from in front of queue.peek() – Get the front element.empty() ...

Implement a trie with insert, search, and startsWith methods.Example:Trie trie = new Trie();trie.insert("apple");trie.search("apple"); // returns truetrie.search("app"); // returns falset...

Given a non-empty array of integers, every element appears three times except for one, which appears exactly once. Find that single one.Note:Your algorithm should have a linear runtime complexity. C...

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 tree...

Implement int sqrt(int x).Compute and return the square root of x, where x is guaranteed to be a non-negative integer.Since the return type is an integer, the decimal digits are truncated and only t...

Given a string s consists of upper/lower-case alphabets and empty space characters ’ ', return the length of last word in the string.If the last word does not exist, return 0.Note: A word is defined...

Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.Example:Input: [-2,1,-3,4,-1,2,1,-5,4],Output: 6Explanation:...

Given an array of strings, group anagrams together.Example:Input: ["eat", "tea", "tan", "ate", "nat", "bat"],Output:[ ["ate","eat","tea"], ["nat","tan"], ["bat"]]Note:All inputs will be ...

Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinations in candidates where the candidate numbers sums to target.The same repeate...

Given an array of integers nums sorted in ascending order, find the starting and ending position of a given target value.Your algorithm’s runtime complexity must be in the order of O(log n).If the t...

Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at least twice in the array, and it should return false if every element is

Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the absolute difference between i and j is at most k.im

Given an integer, write a function to determine if it is a power of two.Credits: Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.public class Solution {

Invert a binary tree. 4 / \ 2 7 / \ / \1 3 6 9to 4 / \ 7 2 / \ / \9 6 3 1Trivia: This problem was inspired by this original tweet by Max Howell: Google:

Implement the following operations of a stack using queues.push(x) – Push element x onto stack. pop() – Removes the element on top of the stack. top() – Get the top element. empty() – Return whether

Given a singly linked list, determine if it is a palindrome.Follow up: Could you do it in O(n) time and O(1) space?/** * Definition for singly-linked list. * public class ListNode { * int val;

Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two

Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.Supposed the linked list is 1 -> 2 -> 3 -> 4 and you are given the third node with value 3, t

Given two strings s and t, write a function to determine if t is an anagram of s.For example, s = “anagram”, t = “nagaram”, return true. s = “rat”, t = “car”, return false.Note: You may assume the s

```/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */public class Solution { public ListNode mergeTwoLi

/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */public class Solution { public ListNode addTw

Given a string containing just the characters’(‘,’)’,’{‘,’}’,’[‘and’]’, determine if the input string is valid. The brackets must close in the correct order,”()”and”()[]{}”are all valid but”(]”and”([)

Given an array and a value, remove all instances of that value in place and return the new length.Do not allocate extra space for another array, you must do this in place with constant memory.The order

Given a binary tree, return all root-to-leaf paths.For example, given the following binary tree: 1 / \2 3 \ 5All root-to-leaf paths are:["1->2->5", "1->3"]/** * Definition for a binary tr

Given an array containing n distinct numbers taken from 0, 1, 2, …, n, find the one that is missing from the array.For example, Given nums = [0, 1, 3] return 2.Note: Your algorithm should run in line

You are a product manager and currently leading a team to develop a new product. Unfortunately, the latest version of your product fails the quality check. Since each version is developed based on the

Given an array nums, write a function to move all 0’s to the end of it while maintaining the relative order of the non-zero elements.For example, given nums = [0, 1, 0, 3, 12], after calling your funct

You are playing the following Nim Game with your friend: There is a heap of stones on the table, each time one of you take turns to remove 1 to 3 stones. The one who removes the last stone will be the

Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.Example 1:Input: "Let's take LeetCode contest"Output

Given an array of 2n integers, your task is to group these integers into n pairs of integer, say (a1, b1), (a2, b2), …, (an, bn) which makes sum of min(ai, bi) for all i from 1 to n as large as possibl

Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.Do not allocate extra space for another array, you must do this in place with cons

Given a sorted linked list, delete all duplicates such that each element appear only once.For example, Given 1->1->2, return 1->2. Given 1->1->2->3->3, return 1->2->3./** * Definition for singly-lin