题目地址 题目链接 题解 注,下方\((i,j)\)均指\(gcd(i,j)\),以及证明过程有一定的跳步,请确保自己会莫比乌斯反演的基本套路. 介绍本题的\(O(n)\)和\(O(n\sqrt{n})\)做法,本题还有\(O(nlogn)\)做法,需要用到欧拉函数,或者是从质因子角度考虑也可以得到另外一个\(O(n)\)做法. 题目就是求 \[ \prod_{i=1}^n\prod_{j=1}^n\frac{ij}{(i,j)^2} \] 考虑分解一下 \[ \prod_{i=1}^n\pro…

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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…

Find the contiguous subarray within an array (containing at least one number) which has the largest product. For example, given the array [2,3,-2,4],the contiguous subarray [2,3] has the largest product = 6. 这个求最大子数组乘积问题是由最大子数组之和问题演变而来,但是却比求最大子数组之和要复…

the inner product Givens two vectors \(x,y\in \mathbb{R}^n\), the quantity \(x^\top y\), sometimes called the inner product or dot product of the vectors, is a real number given by: \[x^\top y=\begin{bmatrix}x_1 , x_2 ,\cdots ,x_n \end{bmatrix}\begin…

Find the contiguous subarray within an array (containing at least one number) which has the largest product. For example, given the array [2,3,-2,4],the contiguous subarray [2,3] has the largest product = 6. Since two negative numbers may multiply an…

Find the contiguous subarray within an array (containing at least one number) which has the largest product. For example, given the array [2,3,-2,4],the contiguous subarray [2,3] has the largest product = 6. 子数组乘积最大 class Solution { public: int maxPr…

We all need to know our customers in order to create products they’ll actually buy. This is why the minimum viable audience idea is so powerful. It doesn’t start with the product. It starts with the customer. That means the media you create — the dai…

Given an integers array A. Define B[i] = A[0] * ... * A[i-1] * A[i+1] * ... * A[n-1], calculate B WITHOUT divide operation. Have you met this question in a real interview? Yes Example For A = [1, 2, 3], return [6, 3, 2]. LeetCode上的原题,请参见我之前的博客Product…

使用SSMS 2008客户端工具逆向生成了创建链接服务器的脚本时,在测试环境执行是报如下错误:'(null)' is an invalid product name. USE [master] GO IF EXISTS (SELECT srv.NAME            FROM   sys.servers srv            WHERE  srv.server_id != 0                   AND srv.NAME = N'MES_DB_LINK_TEST'…