sunwinner
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NIghtmare28：
太好用了, 谢谢
Create Local Cloudera Parcels Repo to Save Your ASS -
oyxccyj：
你好，请问下你如上的问题解决了吗？我现在也遇到同样的问题，网上 ...
Homework - HBase Shell, Java Client and MapReduce Job -
20131007：
用java描述算法？
基础数据结构和算法二：Selection sort -
ender35：
第二种实现仅能用于数组排序
计数排序（Counting Sort） -
fy616508150：
我想知道有括号参加运算怎么办
算24算法实现
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In directed graphs, edges are one-way: the pair of vertices that defines each edge is an ordered pair that specifies a one-way adjacency. Many applications (for example, graphs that represent the web, scheduling constraints, or telephone calls) are naturally expressed in terms of directed graphs. ...
Design pattern for graph processing.
Since we consider a large number of graph-processing algorithms, our initial design goal is to decouple our implementations from the graph representation. To do so, we develop, for each given task, a task-specific class so that clients can create objects to ...
A graph is a set of vertices and a collection of edges that each connect a pair of vertices. Vertex names are not important to the definition, but we need a way to refer to vertices. By convention, we use the names 0 through V-1 for the vertices in a V-vertex graph.
Glossary
A substantial amo ...
If you play around array slicing in irb, it will behavior like below:
irb(main):027:0> a = [1,2,3]
=> [1, 2, 3]
irb(main):028:0> a[2,1]
=> [3]
irb(main):029:0> a[4,1]
=> nil
irb(main):030:0> a[3,1]
=> []
The weird behavior is that sometimes it return ...
Enumerable#inject是Ruby核心库中的一个简洁而且强大的API，今天读到一段简洁的代码之后，对这个API产生了浓厚的兴趣，索性搜寻一下资料，总结一下它的用法。
代码如下：
def text_at(*args)
args.inject(@feed) { |s, r| s.send(:at, r)}.inner_text
end
这段代码完成的功能是：取出XML文件中某子元素的文本内容，它是用nokogiri库来完成这个功能的。关于Nokogiri库API（at(), inner_text()）的细节我们不谈，只是用这段代码来引起你对inject的兴趣，现 ...
Today I was trapped by kind of wierd behavior of Ruby's String#split, here's an example:
def parse_inline_styles(text)
segments = text.split(%r{(</?.*?>)}).reject {|x| x.empty?}
segments.size == 1 ? segments.first : segments
end
This code snippet parse text string by <b>, < ...
Search algorithms that use hashing consist of two separate parts. The first part is to compute a hash function that transforms the search key into an array index. Ideally, different keys would map to different indices. This ideal is generally beyond our reach, so we have to face the possibility t ...
The insertion algorithm for 2-3 trees just described is not difficult to understand; now, we will see that it is also not difficult to implement. We will consider a simple representation known as a red-black BST that leads to a natural implementation.
Encoding 3-nodes. The basic idea behind ...
Binary search tree works well for a wide variety of applications, but they have poor worst-case performance. Now we introduce a type of binary search tree where costs are guaranteed to be logarithmic, no matter what sequence of keys is used to construct them. Ideally, we would like to keep our b ...
A binary search tree (BST) is a binary tree where each node has a Comparable key (and an associated value) and satisfies the restriction that the key in any node is larger than the keys in all nodes in that node’s left subtree and smaller than the keys in all nodes in that node’s right subtree.
...
Binary search needs an ordered array so that it can use array indexing to dramatically reduce the number of compares required for each search, using the classic and venerable binary search algorithm. We maintain indices into the sorted key array that delimit the subar- ray that might contain the se ...
Some important applications of priority queues include simulation systems, where the keys correspond to event times, to be processed in chronological order; job scheduling, where the keys correspond to priorities indicating which tasks are to be performed first; and numerical computations, where th ...
Quick sort is probably used more widely than any other. It is popular because it is not difficult to implement, works well for a variety of different kinds of input data, and is substantially faster than any other sorting method in typical applications. The quicksort algorithm’s desirable features ...
One of mergesort’s most attractive properties is that it guarantees to sort any array of N items in time proportional to N * log N. Its prime disadvantage is that it uses extra space proportional to N.
Top-down mergesort
It is one of the best-known examples of the utility of the divide- ...