In this little training challenge, you are going to learn about the Robots_exclusion_standard.The robots.txt file is used by web crawlers to check if they are allowed to crawl and index your website or only parts of it.Sometimes these files reveal th…

Your task is simple:Find the first two primes above 1 million, whose separate digit sums are also prime.As example take 23, which is a prime whose digit sum, 5, is also prime.The solution is the concatination of the two numbers,Example: If the first…

MarkdownPad Document html,body,div,span,applet,object,iframe,h1,h2,h3,h4,h5,h6,p,blockquote,pre,a,abbr,acronym,address,big,cite,code,del,dfn,em,img,ins,kbd,q,s,samp,small,strike,strong,sub,sup,tt,var,b,u,i,center,dl,dt,dd,ol,ul,li,fieldset,form,label…

今天开始打一打wechall 累了打wechall,不累的时候开始打buu 第一题:Get Sourced 查看源代码即可,拉到底部 第二题:Stegano 属于misc的范畴,直接下载下来,然后notepad++查看,在最后有一个passwd:steganoI 直接丢上去提交即可 第三题: Crypto - Caesar 凯撒密码,位移一位 是英文,is后面那一串就是密码 第四题:WWW-Robots 根据提示,直接http://www.wechall.net/robots.txt 然后读取之…

目录 0x00 Wechall writeup Training: Get Sourced Training: ASCII Encodings: URL Training: Stegano I Training: WWW-Robots Training: Crypto - Caesar I PHP 0817 Prime Factory Training: MySQL I Stegano Attachment Zebra Training: Crypto - Transposition I hi…

比赛时候面向过题队伍数目 打表- - 看了题解发现确实是这么回事,分析能力太差.. /* HDU 6063 - RXD and math [ 数学,规律 ] | 2017 Multi-University Training Contest 3 题意: 求 Σ μ(i)^2 * sqrt( n^k/i ) [ 1 <= i<= n^k ] n,k <= 1e18 分析: 首先 μ(i) 为莫比乌斯函数,若 i 是完全平方数的倍数则 μ(i) = 0 ,否则 μ(i) = ±1 所以只有不是…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=6063 题目意思:字面意思,给出n,k,算出这个式子的答案. 思路:比赛的时候是打表找规律过了,赛后仔细研究一下数学上的具体做法,首先莫比乌斯函数,就是他后面给的那个式子μ(n)=(−1)k(n=p1p2…pk)   p1,p2,p3…pk是互不相同的的素数.满足这个条件的n,μ^2(n)=1,否则μ^2(n)=0:从这个定义里面我们发现所有满足μ^2(n)=0的n值必定满足n=a^2*b,其中μ^2…

让你在平面上取一个点,使得其到给定的所有点的距离和最小. 就是“费马点”. 模拟退火……日后学习一下,这是从网上扒的,先存下. #include<iostream> #include<cstdio> #include<cstdlib> #include<cmath> #include<ctime> using namespace std; int n; double xx,yy,ans,t; struct point{double x,y;}p[…

[Link]: [Description] [Solution] 发现1010mod(109+7)=999999937; 猜测答案是nk 写个快速幂; 注意对底数先取模; [NumberOf WA] 1 [Reviw] 看到过的人那么多就应该想到找规律的. 大胆猜测 [Code] #include <bits/stdc++.h> using namespace std; #define int long long const int MOD = 1e9+7; int n,k; int get_…

2014 Multi-University Training Contest 9#6 Fast Matrix CalculationTime Limit: 2000/1000 MS (Java/Others)    Memory Limit: 131072/131072 K (Java/Others)Total Submission(s): 424    Accepted Submission(s): 219 Problem Description One day, Alice and Bob…