Smith Number Time Limit: 1 Sec  Memory Limit: 64 MB Submit: 825  Solved: 366 Description While skimming his phone directory in 1982, Albert Wilansky, a mathematician of Lehigh University,noticed that the telephone number of his brother-in-law H. Smit…

公式推导题,G(0) = 1,G(1) = t,给出一个 i 和 G(i),要求求出G(j)的值: G(0) = 0*t + 1 G(1) = 1*t + 0; 观察t的系数和常数值可以知道二者都遵循斐波那契的规律,设系数值为Y(n),常数值为X(n); G(2) = 1*t + 1; Y(0) = 0,Y(1) = 1; G(3) = 2*t + 1; X(0) = 1, X(1) = 0; G(4) = 3*t + 2; 这样就能求出答案了,最后的t满足要求就有解 G(5) = 5*t +…

关于不同进制数之间转换的数学推导 涉及范围:正整数范围内二进制(Binary),八进制(Octonary),十进制(Decimal),十六进制(hexadecimal)之间的转换 数的进制有多种,比如两双袜子为一双就采用二进制,平常的一周七天就采用七进制,每小时有六十分钟就采用六十进制.在计算机科学中我们经常用的有二进制,八进制,十进制,十六进制.计算机只能识别0和1组成的数字,但由于当一个数字比较大的时候,二进制的长度将变得非常长,对于人来说可读性非常差,而进制越大,那么数据显示的长度便越短,…

UVA - 10014 Simple calculations Time Limit: 3000MS Memory Limit: Unknown 64bit IO Format: %lld & %llu id=19100" style="color:blue">Submit Status Description  Simple calculations  id=19100" style="color:blue">The Pro…

Poj1142 Smith Numbers Smith Numbers Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 13854 Accepted: 4716 Description While skimming his phone directory in 1982, Albert Wilansky, a mathematician of Lehigh University,noticed that the telepho…

Galaxy Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others) Total Submission(s): 556    Accepted Submission(s): 127 Special Judge Problem Description Good news for us: to release the financial pressure, the government…

Friend HDU - 1719 Friend number are defined recursively as follows. (1) numbers 1 and 2 are friend number; (2) if a and b are friend numbers, so is ab+a+b; (3) only the numbers defined in (1) and (2) are friend number. Now your task is to judge wheth…

上篇记录了一些决策树算法,这篇是借OC-SVM填回SMO在SVM中的数学推导这个坑. 参考文献: http://research.microsoft.com/pubs/69644/tr-98-14.pdf https://inst.eecs.berkeley.edu/~ee227a/fa10/login/l_dual_strong.html https://inst.eecs.berkeley.edu/~ee127a/book/login/l_sdual_slater.html http://w…

sumdiv(POJ 1845) Description 给定两个自然数A和B,S为A^B的所有正整数约数和,编程输出S mod 9901的结果. Input Format 只有一行,两个用空格隔开的自然数A和B(0<=A,B<= 50000000). Output Format 只有一行,即S mod 9901的结果. Sample Input 2 3 Sample Output 15 解析 这是一道数学推导+分治的简单运用,大体思路如下. 由算数基本定理可得: \[A=p_1^{a_1}*…

本来是要调研 Latent Dirichlet Allocation 的那个 LDA 的, 没想到查到很多关于 Linear Discriminant Analysis 这个 LDA 的资料.初步看了看,觉得数学味挺浓,一时引起了很大的兴趣:再看看,就有整理一份资料的冲动了.网上查到的相关文章大都写得不是很详细,而且在概念和记号等方面也比较混乱,因此,在整理本文时,我有意识地牵了一根主线,想让读者读起来有循序渐进的感觉,记号上也力求规范和统一.期间参考了若干文献,以及一些优秀的博客,如 Jerr…

Given a positive integer n, break it into the sum of at least two positive integers and maximize the product of those integers. Return the maximum product you can get. For example, given n = 2, return 1 (2 = 1 + 1); given n = 10, return 36 (10 = 3 +…

题面 传送门 思路 看到这道题,我的第一想法是前缀和瞎搞,说不定能$O\left(n\right)$? 事实证明我的确是瞎扯...... 题目中的提示 这道题的数据中告诉了我们: $sum\left(s\left[i\right]\right)<=50000$ 也就是说,总长度是很小的,这提示我们往"通过长度来解题"的方向上想 那么,最便捷的处理区间长度和的算法是什么呢?前缀和 我们需要求什么? 做题的过程中,一定不能忘记这一点:我们要求的是,所有长度为s的区间的愉悦值总和 那么…

要点: 1.期望的套路,要求n以上的期望,则设dp[i]为i分距离终点的期望步数,则终点dp值为0,答案是dp[0]. 2.此题主要在于数学推导,一方面是要写出dp[i] = 什么,虽然一大串但是思维上并不难:然后就是一种解方程的方法,因为都跟dp[0]有关,且dp[0]是个确定的常数,所以设dp[i] = A[i] * dp[0] + B[i],带入上面那一串解出A[i].B[i],发现是个递推式,于是递推求出A[i]B[i]即可得到dp[0] = B[0] / (1 - A[0]).推荐邝斌…

题解: 考场上靠打表找规律切的题,不过严谨的数学推导才是本题精妙所在:求:$\sum\prod_{i=1}^{m}F_{a{i}}$ 设 $f(i)$ 为 $N=i$ 时的答案,$F_{i}$ 为斐波那契数列第 $i$ 项.由于 $a$ 序列是有序的,要求的答案可以表示成:$f(i)=\sum_{j=1}^{i}f(j)*F_{i-j}$由于斐波那契数列第 0 项是 0,显然可以表示成:$f(i)=\sum_{j=1}^{i-1}f(j)*F_{i-j}$考虑一下 $f(i+1)$ 和 $f(i…

Harmonic Number (II) Time Limit: 3000MS   Memory Limit: 32768KB   64bit IO Format: %lld & %llu Submit Status Description I was trying to solve problem '1234 - Harmonic Number', I wrote the following code long long H( int n ) {     ;     ; i <= n; i…

A - A Very Easy Triangle Counting Game Time Limit:1000MS     Memory Limit:64000KB     64bit IO Format:%lld & %llu Submit Status Practice ACdream 1008 Description Speedcell and Shoutmon love triangles very much.One day,they are playing a game named “T…

Problem Description   You live in a village but work in another village. You decided to follow the straight path between your house (A) and the working place (B), but there are several rivers you need to cross. Assume B is to the right of A, and all…

从今天开始就有各站网络赛了 今天是ccpc全国赛的网络赛 希望一切顺利 可以去一次吉大 希望还能去一次大连 题意: 很明确是让你求Sn=[a+sqrt(b)^n]%m 思路: 一开始以为是水题 暴力了一发没过 上网看了一下才知道是快速幂 而且特征方程的推导简直精妙 尤其是共轭相抵消的构造 真的是太看能力了 (下图转自某大神博客) 特征方程是C^2=-2*a*C+(a*a-b) 然后用快速幂求解 临时学了下矩阵快速幂 从这道题能看出来 弄ACM真的要数学好 这不是学校认知的高数 线代 概率分数 而…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5312 Sequence Time Limit: 2000/2000 MS (Java/Others)    Memory Limit: 262144/262144 K (Java/Others) Total Submission(s): 1336    Accepted Submission(s): 410 Problem Description Today, Soda has learned a…

Problem Description In many applications very large integers numbers are required. Some of these applications are using keys for secure transmission of data, encryption, etc. In this problem you are given a number, you have to determine the number of…

SRM 146 2 500RectangularGrid Problem Statement Given the width and height of a rectangular grid, return the total number of rectangles (NOT counting squares) that can be found on this grid. For example, width = 3, height = 3 (see diagram below): __ _…

C. Divisibility by Eight time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a non-negative integer n, its decimal representation consists of at most 100 digits and doesn't conta…

D. Mike and Feet time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Mike is the president of country What-The-Fatherland. There are n bears living in this country besides Mike. All of them are…

GCD Expectation Time Limit: 4 Seconds                                     Memory Limit: 262144 KB                             Edward has a set of n integers {a1, a2,...,an}. He randomly picks a nonempty subset {x1, x2,…,xm} (each nonempty subset has…

 LCM Challenge Time Limit:1000MS     Memory Limit:64000KB     64bit IO Format:%lld & %llu Submit Status Practice ACdream 1077 Description Some days ago, I learned the concept of LCM (least common multiple). I've played with it for several times and I…

Rikka with wood sticks Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 600    Accepted Submission(s): 169 Problem Description As we know, Rikka is poor at math. Yuta is worrying about this situa…

Rescue The Princess Time Limit: 1 Sec  Memory Limit: 128 MB Submit: 412  Solved: 168 [Submit][Status][Web Board] Description Several days ago, a beast caught a beautiful princess and the princess was put in prison. To rescue the princess, a prince wh…

Triangle Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 0    Accepted Submission(s): 0 Problem Description This is a simple question, give you a triangle, please divide the triangle into two p…

DNA Alignment time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Vasya became interested in bioinformatics. He's going to write an article about similar cyclic DNA sequences, so he invented a…

E. Tetrahedron 分类: AC路漫漫2013-08-08 16:07 465人阅读 评论(0) 收藏 举报 time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a tetrahedron. Let's mark its vertices with letters A, B, C and D …