Time complexity wise this solution is the best among all, we can do all operations in O(1) time. 时间复杂度这个解决方案是最好的,我们可以在O(1)时间内完成所有操作.(还是说经过时间检验的?)…

转自:https://www.jianshu.com/p/59d09b9cee58 每一个优秀的开发者脑中都有时间概念.他们想给用户更多的时间让用户做他们想做的事情.他们通过最小化时间复杂度来实现这一目的. 在你能理解程序的时间复杂度之前,你需要了解最常使用它的地方:算法设计. 所以究竟什么是算法? 简单来说,算法就是一系列被控制的步骤,你通过按序执行这些步骤可以实现一些目标或者产生一些输出.让我们以你祖母烘烤蛋糕的菜单为例子.等等,这也可以算作算法?当然算! function 烘烤蛋糕(风味,…

137. Single Number II Given an array of integers, every element appears three times except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 记录32个bit每个bit出现的…

1. 普通的二分法查找查找等于target的数字 2. 还可以查找小于target的数字中最小的数字和大于target的数字中最大的数字 由于新的查找结果总是比旧的查找结果更接近于target,因此只需不停更新result 3. 查找最接近于target的数字 这种情况下,新的查找结果不一定比旧的查找结果更接近target,所以要比较他们与target的差值. 题目: 74. Search a 2D Matrix Write an efficient algorithm that searche…

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). For example, given [1,2,3,4], return [24,12,8,6]. Fo…

D. Regular Bridge time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output An undirected graph is called k-regular, if the degrees of all its vertices are equal k. An edge of a connected graph is c…

Given two Binary Search Trees, find common nodes in them. In other words, find intersection of two BSTs. Example: from: http://www.geeksforgeeks.org/print-common-nodes-in-two-binary-search-trees/ Method 1 (Simple Solution) A simple way is to one by o…

首先输出个\(\LaTeX\ \),看上去非常高端! 然后上论文,测试以后发现不行QAQQQ 貌似只能插入一个公式来着...比如:$\theta(\vec{u},\ \vec{v}) = arccos(\frac {\vec{u} \cdot \vec{v}} {|\vec{u}| \ |\vec{v}|})$ 不过貌似加载公式挺快的!恩恩恩 以后就有写题解更简单了!赞 $$y = \frac{g} {-2 * cos^{2}\theta * v_{0}^ {2}} * x ^ {2} + ta…

题目: Given a set of distinct integers, S, return all possible subsets. Note: Elements in a subset must be in non-descending order. The solution set must not contain duplicate subsets. For example,If S = [1,2,3], a solution is: [ [3], [1], [2], [1,2,3]…

Single Number III Given an array of numbers nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once. For example: Given nums = [1, 2, 1, 3, 2, 5], return [3, 5]…