题解: 首先分析一下这个问题 发现等价于是求n之内与n互素的数的个数,即欧拉函数 这个可以线性筛 但发现还应该减去$x^2==1$的情况 这个东西不是那么好处理 考虑用中国剩余定理拆 因为$p1^{a1}*p2^{a2}*p3^{a3}....$这些是互素的 所以拆完后的方程的解和原方程是唯一对应的 问题变成$x^2 \equiv 1  (mod \ pi^{ai})$ 移项变成$(x-1)(x+1) \equiv1 (mod \ pi^{ai})$ 注意到当$pi>2$时$pi$不可能同时整除…

题目链接 loj 题解 感谢珂神的指导orz 观察式子\(i \times j \equiv 1 \pmod m\),显然\(i,j\)是模\(m\)意义下成对的逆元,只需统计模\(m\)意义下存在逆元的数的个数,即与\(m\)互质的数的个数\(\varphi(m)\) 每对逆元的连边有两种情况,记逆元对数为\(x\),则方案数为\(2^x\) 真的完了吗?难点才刚开始 模\(m\)意义下有的数逆元为本身!此时不能计入答案 所以我们还需求模\(m\)意义下逆元为本身的数的个数 重新理解一下中国剩…

TimeWall is a graph databases github It be used to apply mathematic model and social network with graph algorithms and so on... Features: 1. C/S structure 2. compute in memory 3. dynamic add and remove nodes on the graph db 4. with lots of algorithms…

Source: Connected Brain Figure above: Bullmore E, Sporns O. Complex brain networks: graph theoretical analysis of structural and functional systems.[J]. Nature Reviews Neuroscience, 2009, 10(3):186-198. Graph measures A graph G consisting of a set of…

Destroying The Graph Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 8198   Accepted: 2635   Special Judge Description Alice and Bob play the following game. First, Alice draws some directed graph with N vertices and M arcs. After that B…

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected graph. Example 1: 0          3 |          | 1 --- 2    4 Given n = 5 and…

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to check whether these edges make up a valid tree. For example: Given n = 5 and edges = [[0, 1], [0, 2], [0, 3], [1, 4]], return tru…

Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors. OJ's undirected graph serialization: Nodes are labeled uniquely. We use # as a separator for each node, and , as a separator for node label and each neigh…

Influence maximization on big social graph Fanju PPT链接: social influence booming of online social network 一, Application:viral marketing 1, identify influence customers: seeds. 2, convince them to adopter product. other application: Rumor monitoring…

关于zabbix的API见,zabbixAPI 1item批量添加 我是根据我这边的具体情况来做的,本来想在模板里面添加item,但是看了看API不支持,只是支持在host里面添加,所以我先在一个host里面添加,然后在将item全部移动到模板里. 具体步骤就不说了,直接上代码: 为了快速完成,代码写的有点乱,也没怎么处理异常,算是第一版吧,有时间在优化  1 #!/usr/bin/env python #-*- coding: utf- -*- import json import sys i…