Difficulty: Medium  More:[目录]LeetCode Java实现 Description Given a sorted integer array where the range of elements are [0, 99] inclusive, return itsmissing ranges.For example, given [0, 1, 3, 50, 75], return [“2”, “4->49”, “51->74”, “76->99”]Examp…

作者: 负雪明烛 id: fuxuemingzhu 个人博客:http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 遍历 日期 题目地址:https://leetcode-cn.com/problems/missing-ranges/ 题目描述 Given a sorted integer array nums, where the range of elements are in the inclusive range [lower, upper], return…

[LeetCode]First Missing Positive Given an unsorted integer array, find the first missing positive integer. For example, Given [1,2,0] return 3, and [3,4,-1,1] return 2. Your algorithm should run in O(n) time and uses constant space. 找到第一个没有出现的正整数 思路:…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址:https://leetcode.com/problems/smallest-range-ii/description/ 题目描述 Given an array A of integers, for each integer A[i] we need to choose either x = -K or x = K, and add…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 求和 异或 日期 题目地址:https://leetcode.com/problems/missing-number/#/description 题目描述 Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is miss…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址: https://leetcode.com/problems/smallest-range/description/ 题目描述: You have k lists of sorted integers in ascending order. Find the smallest range that includes at least one number from each…

First Missing Positive Given an unsorted integer array, find the first missing positive integer. For example,Given [1,2,0] return 3,and [3,4,-1,1] return 2. Your algorithm should run in O(n) time and uses constant space. 通过swap操作,把各个元素swap到相应的位置上,然后再…

Given an unsorted integer array, find the first missing positive integer. For example,Given [1,2,0] return 3,and [3,4,-1,1] return 2. Your algorithm should run in O(n) time and uses constant space. 思路: 又是一个不让排序,但是要得到跟排序有关信息的.想了半天,只能空间换时间,可是又只能用常量空间,这…

Missing Number 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 linear runtime complexity. Could you i…

题目如下: 解题思路:题目很简单.先对数组排序,根据最大值和最小值即可求出公差,然后遍历数组,计算相邻元素的差,如果差不等于公差,即表示数字缺失. 代码如下: class Solution(object): def missingNumber(self, arr): """ :type arr: List[int] :rtype: int """ arr.sort() diff = (arr[-1] - arr[0])/(len(arr)) fo…

题目如下: 解题思路:我的思路是先找出最大值.对于数组中任意一个元素A[i]来说,如果A[i] + K 是B中的最大值,那么意味着从A[i+1]开始的元素都要减去K,即如果有A[i] + K >= A[-1] - K,那么A[i] + K 就可以作为最大值而存在:如果A[i] + K是最大值,那么最大的最小值是多少呢?因为A[i] 左边的元素都比A[i]小,所以其左边的元素都可以加上K,最大的最小值就会在 A[0] + K 和 A[i+1] - K 之间产生.遍历数组,计算每一个A[i] + K…

作者: 负雪明烛 id: fuxuemingzhu 个人博客:http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 遍历 日期 题目地址:https://leetcode-cn.com/problems/missing-element-in-sorted-array/ 题目描述 Given a sorted array A of unique numbers, find the K-th missing number starting from the leftmo…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 数学计算 日期 题目地址:https://leetcode.com/problems/smallest-range-i/description/ 题目描述 Given an array A of integers, for each integer A[i] we may choose any x with -K <= x <= K, and ad…

题目如下: 解题思路:简单的不能再简单的题目了,对于任意一个A[i]来说,其可能的最小的最大值是A[i]-K,最大的最小值是A[i]+K.遍历数组,求出所有元素中最大的最小值和最小的最大值,两者之差(小于零则取零)就是答案. 代码如下: class Solution(object): def smallestRangeI(self, A, K): """ :type A: List[int] :type K: int :rtype: int """…

[LeetCode]201. Bitwise AND of Numbers Range 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/bitwise-and-of-numbers-range/description/ 题目描述: Given a range [m, n] where 0 <= m <= n <= 2147483647, return the bitwise AND of all numbers i…

题目如下: 解题思路:这题看起来和[leetcode]448. Find All Numbers Disappeared in an Array很相似,但是有几点不同:一是本题的输入存在负数,二是没有约定输入元素的最大值.那么,怎么可以把本题转换成448题的场景呢?首先,我们可以求出输入数组nums中所有正整数的数量,记为p,那么显然能得出这个结论:1 <=answer < p+1.然后,我们可以通过交换把所有值不在这个区间内的元素值移动到数组的后半部分.记nums前半部分[0:length]…

写在前面   老粉丝可能知道现阶段的LeetCode刷题将按照某一个特定的专题进行,之前的[贪心算法]已经结束,虽然只有三个题却包含了简单,中等,困难这三个维度,今天介绍的是第二个专题[数组] 数组(Array)是一种线性表数据结构.它用一组连续的内存空间,来存储一组具有相同类型的数据.在每一种编程语言中,基本都会有数组这种数据类型.不过,它不仅仅是一种编程语言中的数据类型,还是一种最基础的数据结构. 贪心算法回顾: [LeetCode]贪心算法--买卖股票的最佳时机II(122) [LeetC…

题目如下: An integer has sequential digits if and only if each digit in the number is one more than the previous digit. Return a sorted list of all the integers in the range [low, high] inclusive that have sequential digits. Example 1: Input: low = 100,…

题目等级:4Sum II(Medium) 题目描述: Given four lists A, B, C, D of integer values, compute how many tuples (i, j, k, l) there are such that A[i] + B[j] + C[k] + D[l] is zero. To make problem a bit easier, all A, B, C, D have same length of N where 0 ≤ N ≤ 500…

链接:https://leetcode.com/tag/binary-search-tree/ [220]Contains Duplicate III (2019年4月20日) (好题) Given an array of integers, find out whether there are two distinct indices i and j in the array such that the absolute difference between nums[i] and nums[…

题目如下: Given an array of scores that are non-negative integers. Player 1 picks one of the numbers from either end of the array followed by the player 2 and then player 1 and so on. Each time a player picks a number, that number will not be available f…

题目如下: 解题思路:本题和[leetcode]583. Delete Operation for Two Strings 类似,区别在于word1[i] != word2[j]的时候,是删除word1[i]还是word2[j]取决于min(dp[i-1][j]+ord(word1[i-1]),dp[i][j-1]+ord(word2[j-1])). 代码如下: class Solution(object): def minimumDeleteSum(self, s1, s2): ""…

链接:https://leetcode.com/tag/divide-and-conquer/ [4]Median of Two Sorted Arrays [23]Merge k Sorted Lists [53]Maximum Subarray (2019年1月23日, 谷歌tag复习) 最大子段和. 题解: follow up 是divide and conquer If you have figured out the O(n) solution, try coding another…

题目如下: We are given a linked list with head as the first node.  Let's number the nodes in the list: node_1, node_2, node_3, ... etc. Each node may have a next larger value: for node_i, next_larger(node_i) is the node_j.val such that j > i, node_j.val…

题目如下: Given an array A of positive integers, A[i]represents the value of the i-th sightseeing spot, and two sightseeing spots i and j have distance j - i between them. The score of a pair (i < j) of sightseeing spots is (A[i] + A[j] + i - j) : the su…

题目如下: 解题思路:几乎和[leetcode]719. Find K-th Smallest Pair Distance 的方法一样.只不过一个是减法一个是乘法,还有一点区别是[leetcode]719. Find K-th Smallest Pair Distance中i-j和j-i只算一个元素,而本题中i*j与j*i算两个元素. 代码如下: class Solution(object): def findKthNumber(self, m, n, k): """ :ty…

题目如下: 解题思路:本题和[leetcode]97. Interleaving String非常相似,同样可以采用动态规划的方法.记dp[i][j] = 1或者0 表示pattern[0:i]是否匹配string[0:j] ,如果pattern[i] == string[j] 或者 pattern[i] == '?',那么dp[i][j]  = dp[i-1][j-1]:如果pattern[i] = '*' 则复杂一些,因为'*'可以匹配s[j-1],s[j] 或者不匹配,因此只要满足其中任意…

题目如下: 解题思路:我的想法对于数组中任意一个元素,找出其左右两边最近的小于自己的元素.例如[1,3,2,4,5,1],元素2左边比自己小的元素是1,那么大于自己的区间就是[3],右边的区间就是[4,5].那么对于元素2来说,和左边区间合并组成[2,3]以及和右边区间合并组成[2,4,5],这两段区间包括2在内的所有subarray的最小值都是2,其分别可以组成的subarry的个数是 len([3])和len([4,5]),左右区间合并在一起可以组成的subarray的个数是len([3])…

题目如下: On an NxN chessboard, a knight starts at the r-th row and c-th column and attempts to make exactly K moves. The rows and columns are 0 indexed, so the top-left square is (0, 0), and the bottom-right square is (N-1, N-1). A chess knight has 8 po…

题目如下: Given a set of points in the xy-plane, determine the minimum area of any rectangle formed from these points, with sides not necessarily parallel to the x and y axes. If there isn't any rectangle, return 0. Example 1: Input: [[1,2],[2,1],[1,0],[…