Tongust-优快云博客

原创 Kalman Filter

Kalman Filter1 Linear Optimal Filtering2 Orthogonality Principle4 State Model5 Objective And HypothesisObjectiveHypothesisRemark3 NotationsRemarkPropositionConclusion of Space RelationshipT

2017-05-21 15:33:40 513

原创 Leetcode-DSF-Scramble String

思路ProblemCode思路此题有两难。其一规律很难找寻，寻找scramble string 之间的关系需要敏锐的眼光。没有快捷的算法，stack, DP, DC等等行不通，需尝试最傻的方法DSF。 ProblemGiven a string s1, we may represent it as a binary tree by partitioning it to t

2017-05-12 11:02:28 371

原创 Leetcode-2D Dynamic Programming

97. Interleaving StringGiven s1, s2, s3, find whether s3 is formed by the interleaving of s1 and s2.For example, Given: s1 = “aabcc”, s2 = “dbbca”, When s3 = “aadbbcbcac”, return true. When

2017-05-04 00:45:34 300

原创 Leetcode-Reverse words in string

Given an input string, reverse the string word by word.For example, Given s = “the sky is blue”, return “blue is sky the”.Update (2015-02-12): For C programmers: Try to solve it in-place in O(1) s

2017-05-03 23:45:40 273

原创 Newto-Raphson

Newton-Raphson一阶形式推导过程二阶形式推导过程Convex FunctionQuadratic Program1. Newton-Raphson解决f(x)=0f(x)=0问题的逼近方式一阶形式xnew=xold−f(x)f′(x)f′(x)=∂f(x)∂xx^{new} = x^{old}-\frac{f(x)}{f'(x)}\\f'(x) = \frac{\par

2017-05-03 22:38:10 320

原创 Iterative Reweighted Least Squares

逼近 approximation加权最小二乘weighted least squared error approximation逼近其他范式IRLS逼近 lpl_p normOverdetermined system N pAlgebra 方法IRLS for Logit RegressionModeling本文基于这篇paper。逼近（approximation）对于线性的问题，

2017-05-03 21:27:21 2807 1

原创 Leetcode-Recover Binary Search Tree

Two elements of a binary search tree (BST) are swapped by mistake.Recover the tree without changing its structure.Note: A solution using O(n) space is pretty straight forward. Could you devise a const

2017-05-03 10:41:55 228

原创 TCP/IP

TCP 与 UDP的区别 TCP面向连接（如打电话要先拨号建立连接）;UDP是无连接的，即发送数据之前不需要建立连接 TCP提供可靠的服务。也就是说，通过TCP连接传送的数据，无差错，不丢失，不重复，且按序到达;UDP尽最大努力交付，即不保证可靠交付 TCP面向字节流，实际上是TCP把数据看成一连串无结构的字节流;UDP是面向报文的 UDP没有拥塞控制，因此网络出现拥塞

2017-04-28 23:45:17 574

原创 g++

各种flag生成静态和动态链接库的方法静态链接库 a动态链接库 so各种flag-L Library directive. 链接库的文件夹，分别是动态和静态链接库： shared library directive containing xx.so 动态链接库 archive fie directive including xx.a 静态链接库-l Link the li

2017-04-28 16:07:29 227

原创 ESL-ICA

Independent Component AnalysisICA Maximum LikelihoodSigmoid functionFastICAWhitenPython ImplementIndependent Component Analysis假设x∈ℝp×1x\in \mathbb{R}^{p\times 1}是观测直，s∈ℝp×1s\in \mathbb{R}^{p\tim

2017-04-27 01:20:04 857

原创 Gap Statistic 间隔统计量

Gap Statistic聚类的紧支测度 measure of the compactness间隔统计量GSPython 实现测试Gap StatisticGap statistic由Tibshirani等人提出，用以解决聚类问题确定所判定类的数目。聚类的紧支测度（measure of the compactness）最简单的方法是使用类内样本点之间的欧式距离来表示，记为DkD_k，DKD

2017-04-26 01:44:03 24884 7

原创 Leetcode-Graph-Hash

133. Clone GraphClone 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 f

2017-04-25 19:54:22 369

原创面试-C++

C虚函数多线程编程C++C++虚函数详见虚函数表解析有关虚函数的FAQ多线程编程

2017-04-25 18:46:06 228

转载平衡二叉树

AVL http://blog.youkuaiyun.com/whucyl/article/details/17289841 RBT http://blog.youkuaiyun.com/whucyl/article/details/17254801

2017-04-23 13:33:23 188

转载 BST 遍历

递归遍历pre_order// 递归先序遍历 void rpre_order(btree* tree) { btNode * p = tree; if (NULL == p) { return; } cout << p->data << " "; rpre_order(p->left); rpre_or

2017-04-23 10:41:35 349

原创 Linux-Pthread

Detach当其他线程调用exit()，分离的线程将会收到影响而终止。Zombie 僵尸线程Not Detached; Non pthread_join() or wait(); 僵尸进程是一个已经结束的进程/线程，但OS保留部分信息以备父进程查询, OS会在结束时清理僵尸进程。僵尸进程在多进程环境下，父进程要长时间运行，期间可能创建子进程，然后子进程有退出时，但是父进程还在运行，这时就

2017-04-21 21:31:37 210

原创 Leetcode-Methodology-Preprocessing

Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero.Note: The solution set must not contain duplic

2017-04-21 14:26:16 211

原创 Leetcode-Hash-List(2)

Design and implement a data structure for Least Frequently Used (LFU) cache. It should support the following operations: get and put.get(key) - Get the value (will always be positive) of the key if the

2017-04-21 01:37:38 215

原创 Leetcode-List-Hash

Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and put.get(key) - Get the value (will always be positive) of the key if the k

2017-04-20 23:16:18 230

原创 Leetcode-DSF-Trie-Backtrack

Word Search IIGiven a 2D board and a list of words from the dictionary, find all words in the board.Each word must be constructed from letters of sequentially adjacent cell, where “adjacent” cells are

2017-04-20 14:49:50 234

原创 Leetcode-Longest Consecutive Sequence

Given an unsorted array of integers, find the length of the longest consecutive elements sequence.For example, Given [100, 4, 200, 1, 3, 2], The longest consecutive elements sequence is [1, 2, 3, 4].

2017-04-20 01:00:49 193

原创 Leetcode-Trie

Add and Search Word - Data structure designDesign a data structure that supports the following two operations:void addWord(word) bool search(word) search(word) can search a literal word or a regular

2017-04-20 00:35:31 257

原创 Linux-SED

Sed (Strem Editor)1. 语法普模式sed [options] {sed-commands} {input-file}批处理sed [options] -f [sed-commands-in-file] {input-file} sed [options] -e [cmd1] -e [cmd2] {input}2. 脚本执行流程R read a line into the patt

2017-04-20 00:33:29 175

原创 TLPI-Ch24

fork()In parent: returns process ID of child on success or -1 on error; in successfully created child: always returns 0. 完成对fork()调用后将存在两个进程，且每个进程都会从fork()的返回处继续执行。#include <unistd.h>#include <iostr

2017-04-16 20:04:09 402

原创 Heap-Find Median from Data Stream

Median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value. So the median is the mean of the two middle value.Examples: [2,3,4] , the median is 3

2017-04-15 22:22:33 300

原创 Build Binary Search Tree

/* LeetCode 536. Construct Binary Tree from String* * You need to construct a binary tree from a string consisting of parenthesis and integers.* * The whole input represents a binary tree. It conta

2017-04-15 16:26:13 280

转载 Linux 常用命令

关键字: linux 查进程、杀进程、起进程 1.查进程 ps命令查找与进程相关的PID号： ps a 显示现行终端机下的所有程序，包括其他用户的程序。 ps -A 显示所有程序。 ps c 列出程序时，显示每个程序真正的指令名称，而不包含路径，参数或常驻服务的标示。 ps -e 此参数的效果和指定”A”参数相同。 ps e 列出程序时，

2017-04-14 23:23:02 186

转载 Linux-Shell chmod

修改权限rwx | rwx | rwx u | g | o 分别代指自己，用户组，其他人的权限：read write excute. drwxrwxr-x chmod 语法一chmod [who] [+, -, =] [mode] xx 命令中各选项的含义为：　　操作对象who可是下述字母中的任一个或者它们的组合：　　u 表示“用户（user）”，即文件或目录的所

2017-04-14 23:13:18 334

原创 One-by-one to solve the Sequence Problem (2)

#1399 : Shortening Sequence (from hihocoder) Stack时间限制:10000ms 单点时限:1000ms 内存限制:256MB描述There is an integer array A1, A2 …AN. Each round you may choose two adjacent integers. If their sum is an odd nu

2017-03-31 15:13:19 238

原创 One-by-one to solve the Sequence Problem (1)

One-by-one to solve the Sequence Problem (1)1400 : Composition （from hihocoder）时间限制:10000ms 单点时限:1000ms 内存限制:256MB 描述 Alice writes an English composition with a length of N characters. However, her

2017-03-31 15:04:22 265

原创统计学习之---多尺度变换 MDS (Multidimensional Scaling)

Multidimensional Scaling (MDS)The idea is to find a set of k-dimensional continuous variables to representation the original data, which only contains the dis-similarity information. It is used in prob

2017-03-26 23:15:11 4623

原创 The solution on the Elements of Statistical Learning

统计学习基础第二版参考答案

2016-12-17 15:22:50 4514

原创算法导论第三版-课后习题-自解

关于答案算法导论课后习题是没有官方版的，虽然可以在https://mitpress.mit.edu/sites/default/files/titles/content/Intro_to_Algo_Selected_Solutions.pdf 中找到官方给的部分答案。按照Cormen的解释，为了讲师布置作业，官方并未公布所有的答案，以便学生自己解答。前十一章答案（仅供参考）俄罗斯一

2015-08-24 17:39:35 11741

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