今天的比赛的题目相对来说比较「直白」,不像前几周都是一些特定的算法,如果你没学过不可能想出来. 做了这些周,对leetcode比赛的题目也发现了一些「规律」. 一般前两道题都很「简单」,只要有想法,直接敲代码就能解出来.更多考察的是结果是否正确,速度其次. 后两道题有些难度 ,不同场次难度不一样,也可能和不同人的水平感受不同.但是肯定比前两道要难. 一般在做后两道题的时候,只要复杂度是对的,一些细节也不用考虑太多.例如数组开的空间大小,一些线性的提前剪枝判断,写不写都可以过.最主要的是复杂度是同…

今天参加了leetcode的周赛,算法比赛,要求速度比较快.有思路就立马启动,不会纠结是否有更好的方法或代码可读性.只要在算法复杂度数量级内,基本上是怎么实现快速就怎么来了. 比赛时先看的第二题,一看题就有了思路,直接用的广度优先搜索,写完提交正确.再一看有人都做了3道题了,应该是职业选手了,要多像他们看齐. 之后看第一题,发现直接用贪心就能做,写了个双重循环,一次过掉. 第三题求最优连续子数组和,想到是动态规划.然后在处理代码细节上花了很长时间,中间提交还错了一次,在十一点半左右提交通过. 再…

周日的比赛的时候正在外面办事,没有参加.赛后看了下题目,几道题除了表面要考的内容,还是有些能发散扩展的地方. 做题目不是最终目的,通过做题发现知识盲区,去研究学习,才能不断提高. 理论和实际是有关系的,一些题目也都有现实意义.计算机的一些模拟操作,通过数学算法,能够大大减轻代码量和算法复杂度. 第一题是机器人在坐标系上直走和转弯,通过简单的模拟就能实现.但是仔细思考发现还能通过线性代数,坐标变换的方式做,这样在实际中计算更快.甚至还可以用复数来做. 实际扫地机器人可能就用到了类似的算法.让他能够…

这周比赛的题目很有特点.几道题都需要找到一定的技巧才能巧妙解决,和以往靠数据结构的题目不太一样. 就是如果懂原理,代码会很简单,如果暴力做,也能做出来,但是十分容易出错. 第四题还挺难想的,想了好久才想明白.这次先讲第四题,然后再讲其他的题目. 下面是详细的题解和思考. 比赛的地址 Weekly Contest 135 https://leetcode-cn.com/contest/weekly-contest-135 移动石子直到连续 II 题目:移动石子直到连续 II(Moving Ston…

LeetCode 2 Add Two Sum 解题报告 LeetCode第二题 Add Two Sum 首先我们看题目要求: 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…

LeetCode 第 165 场周赛 5275. 找出井字棋的获胜者 5276. 不浪费原料的汉堡制作方案 5277. 统计全为 1 的正方形子矩阵 5278. 分割回文串 III C 暴力做的,只能说数据不充分 找出井字棋的获胜者4 题目描述 Description A 和 B 在一个 3 x 3 的网格上玩井字棋. 井字棋游戏的规则如下: 玩家轮流将棋子放在空方格 (" ") 上. 第一个玩家 A 总是用 "X" 作为棋子,而第二个玩家 B 总是用 "…

Leetcode第 217 场周赛 比赛链接:点这里 做完前两题我就知道今天的竞赛我已经结束了 这场比赛思维量还是比较大的. 1673. 找出最具竞争力的子序列 题目 给你一个整数数组 nums 和一个正整数 k ,返回长度为 k 且最具 竞争力 的 nums 子序列. 数组的子序列是从数组中删除一些元素(可能不删除元素)得到的序列. 在子序列 a 和子序列 b 第一个不相同的位置上,如果 a 中的数字小于 b 中对应的数字,那么我们称子序列 a 比子序列 b(相同长度下)更具 竞争力 . 例如…

[LeetCode]376. Wiggle Subsequence 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址: https://leetcode.com/problems/wiggle-subsequence/description/ 题目描述: A sequence of numbers is called a wiggle sequence if the differences betw…

[LeetCode]649. Dota2 Senate 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/dota2-senate/description/ 题目描述: In the world of Dota2, there are two parties: the Radiant and the Dire. The Dota2 sena…

[LeetCode]911. Online Election 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/online-election/description/ 题目描述: In an election, the i-th vote was cast for persons[i] at time times[i]. Now, we…

[LeetCode]886. Possible Bipartition 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/possible-bipartition/description/ 题目描述: Given a set of N people (numbered 1, 2, ..., N), we would like to spli…

[LeetCode]36. Valid Sudoku 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/valid-sudoku/description/ 题目描述: Determine if a 9x9 Sudoku board is valid. Only the filled cells need to be validated ac…

[LeetCode]870. Advantage Shuffle 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/advantage-shuffle/description/ 题目描述: Given two arrays A and B of equal size, the advantage of A with respect to B…

[LeetCode]593. Valid Square 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/valid-square/description/ 题目描述: Given the coordinates of four points in 2D space, return whether the four points could…

[LeetCode]435. Non-overlapping Intervals 解题报告(Python) 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/non-overlapping-intervals/description/ 题目描述: Given a collection of intervals, find the minimum number of…

[LeetCode]838. Push Dominoes 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/push-dominoes/description/ 题目描述: There are N dominoes in a line, and we place each domino vertical…

[LeetCode]498. Diagonal Traverse 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/diagonal-traverse/description/ 题目描述: Given a matrix of M x N elements (M rows, N columns), ret…

[LeetCode]481. Magical String 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/magical-string/description/ 题目描述: A magical string S consists of only '1' and '2' and obeys the f…

[LeetCode]397. Integer Replacement 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/integer-replacement/description/ 题目描述: Given a positive integer n and you can do operations as follow: If n is even, replace n with n/2. If n is odd, you…

[LeetCode]319. Bulb Switcher 解题报告(Python) 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/bulb-switcher/description/ 题目描述: There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the t…

[LeetCode]91. Decode Ways 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/decode-ways/description/ 题目描述: A message containing letters from A-Z is being encoded to numbers usin…

[LeetCode]456. 132 Pattern 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/132-pattern/description/ 题目描述: Given a sequence of n integers a1, a2, -, an, a 132 pattern is a subs…

[LeetCode]853. Car Fleet 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/car-fleet/description/ 题目描述: N cars are going to the same destination along a one lane road. The desti…

[LeetCode]386. Lexicographical Numbers 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/lexicographical-numbers/description/ 题目描述: Given an integer n, return 1 - n in lexicogra…

[LeetCode]390. Elimination Game 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/elimination-game/description/ 题目描述: There is a list of sorted integers from 1 to n. Starting from left to right, remove the first number and every other numb…

[LeetCode]647. Palindromic Substrings 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/palindromic-substrings/description/ 题目描述: Given a string, your task is to count how many palindromic substrings in this string. The substrings with dif…

[LeetCode]392. Is Subsequence 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/is-subsequence/description/ 题目描述: Given a string s and a string t, check if s is subsequence of t. You may assume that there is only lower case English letters…

[LeetCode]722. Remove Comments 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/remove-comments/description/ 题目描述: Given a C++ program, remove comments from it. The program source is an array where source[i] is the i-th line of the source…

[LeetCode]385. Mini Parser 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/mini-parser/description/ 题目描述: Given a nested list of integers represented as a string, implement a parser to deserialize it. Each element is either an integer, o…

[LeetCode]71. Simplify Path 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.me/ 题目地址:https://leetcode.com/problems/simplify-path/description/ 题目描述: Given an absolute path for a file (Unix-style), simplify it. For e…