繁城落叶

本目录只会在一个Tag完成之后更新，实时更新目录：https://github.com/jiajia0/LeetCode。按照LeetCode的Tags来区分的话，目前共有34个Tag，只列出已经解决的题，各分类中按照题目编号排序：Linked List。Solved：21/28 # Title Difficulty 2 Add Two Numbe

Given a non-empty array of digits representing a non-negative integer, plus one to the integer.The digits are stored such that the most significant digit is at the head of the list, and each element...

Alice has a hand of cards, given as an array of integers.Now she wants to rearrange the cards into groups so that each group is size W, and consists of W consecutive cards.Return true if and only i...

In a string S of lowercase letters, these letters form consecutive groups of the same character.For example, a string like S = “abbxxxxzyy” has the groups “a”, “bb”, “xxxx”, “z” and “yy”.Call a gro...

Alice and Bob have candy bars of different sizes: A[i] is the size of the i-th bar of candy that Alice has, and B[j] is the size of the j-th bar of candy that Bob has.Since they are friends, they wo...

An array is monotonic if it is either monotone increasing or monotone decreasing.An array A is monotone increasing if for all i <= j, A[i] <= A[j]. An array A is monotone decreasing if for al...

Given a non-empty, singly linked list with head node head, return a middle node of linked list.If there are two middle nodes, return the second middle node.Example 1:Input: [1,2,3,4,5]Output: N...

Given a matrix A, return the transpose of A.The transpose of a matrix is the matrix flipped over it’s main diagonal, switching the row and column indices of the matrix.Example 1:Input: [[1,2,3],...

Given an array A of non-negative integers, half of the integers in A are odd, and half of the integers are even.Sort the array so that whenever A[i] is odd, i is odd; and whenever A[i] is even, i is...

Given a binary matrix A, we want to flip the image horizontally, then invert it, and return the resulting image.To flip an image horizontally means that each row of the image is reversed. For examp...

Given an array A of non-negative integers, return an array consisting of all the even elements of A, followed by all the odd elements of A.You may return any answer array that satisfies this conditio...

International Morse Code defines a standard encoding where each letter is mapped to a series of dots and dashes, as follows: “a” maps to “.-“, “b” maps to “-…”, “c” maps to “-.-.”, and so on.For con...

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 appea

Find the minimum length word from a given dictionary words, which has all the letters from the string licensePlate. Such a word is said to complete the given string licensePlateHere, for letters we ign

Given a list of daily temperatures, produce a list that, for each day in the input, tells you how many days you would have to wait until a warmer temperature. If there is no future day for which this i

Given an array of integers, every element appears twice except for one. Find that single one.原文：https://leetcode.com/problems/single-number/description/在一写数字中，有一个数字只出现了一次，其余的都出现了两次，找出出现一次的数字。首先可以利用额外的辅

You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water. Grid cells are connected horizontally/vertically (not diagonally). The grid is completely s

Given an integer array with even length, where different numbers in this array represent different kinds of candies. Each number means one candy of the corresponding kind. You need to distribute these

Given a List of words, return the words that can be typed using letters of alphabet on only one row’s of American keyboard like the image below.Example 1: Input: [“Hello”, “Alaska”, “Dad”, “Peace”]

You’re given strings J representing the types of stones that are jewels, and S representing the stones you have. Each character in S is a type of stone you have. You want to know how many of the ston

Find all possible combinations of k numbers that add up to a number n, given that only numbers from 1 to 9 can be used and each combination should be a unique set of numbers.Example 1: Input: k ...

Given an array arr that is a permutation of [0, 1, …, arr.length - 1], we split the array into some number of “chunks” (partitions), and individually sort each chunk. After concatenating them, the re...

Your are given an array of integers prices, for which the i-th element is the price of a given stock on day i; and a non-negative integer fee representing a transaction fee.You may complete as many tra

Say you have an array for which the ith element is the price of a given stock on day i.If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), desi

Given a 2D integer matrix M representing the gray scale of an image, you need to design a smoother to make the gray scale of each cell becomes the average gray scale (rounding down) of all the 8 surrou

Say you have an array for which the ith element is the price of a given stock on day i.Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and

Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist. Assume that there is only one duplicate number, fin

A matrix is Toeplitz if every diagonal from top-left to bottom-right has the same element.Now given an M x N matrix, return True if and only if the matrix is Toeplitz.Example 1: Input: matrix = [[1,2

Given an unsorted array of integers, find the length of longest continuous increasing subsequence (subarray).Example 1: Input: [1,3,5,4,7] Output: 3 Explanation: The longest continuous increasi

A zero-indexed array A of length N contains all integers from 0 to N-1. Find and return the longest length of set S, where S[i] = {A[i], A[A[i]], A[A[A[i]]], … } subjected to the rule below.Suppose the

Given an array containing n distinct numbers taken from 0, 1, 2, …, n, find the one that is missing from the array.Example 1 Input: [3,0,1] Output: 2Example 2 Input: [9,6,4,2,3,5,7,0,1] Outp

Given an integer array, find three numbers whose product is maximum and output the maximum product.Example 1: Input: [1,2,3] Output: 6Example 2: Input: [1,2,3,4] Output: 24给定一个数组，找出三个数产生的乘积

In a given integer array nums, there is always exactly one largest element.Find whether the largest element in the array is at least twice as much as every other number in the array.If it is, return th

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 that is already sorted in ascending order, find two numbers such that they add up to a specific target number.The function twoSum should return indices of the two numbers suc

Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times.You may assume that the array is non-empty and the majority element always

Given an array of n integers where n > 1, nums, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i].Solve it without division and in O(n).

In LOL world, there is a hero called Teemo and his attacking can make his enemy Ashe be in poisoned condition. Now, given the Teemo’s attacking ascending time series towards Ashe and the poisoning time

Given two integers n and k, you need to construct a list which contains n different positive integers ranging from 1 to n and obeys the following requirement: Suppose this list is [a1, a2, a3, … , an],

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