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Radix Tree
In computer science, a radix tree (also radix trie or compact prefix tree or compressed trie) is a data structure that represents a space-optimized trie (prefix tree) in which each node that is the only child is merged with its parent. The result is that the number of children of every internal node is at most the radix of the radix tree, where = 2 for some integer ≥ 1. Unlike regular trees, edges can be labeled with sequences of elements as well as single elements. This makes radix trees much more efficient for small sets (especially if the strings are long) and for sets of strings that share long prefixes. Unlike regular trees (where whole keys are compared ''en masse'' from their beginning up to the point of inequality), the key at each node is compared chunk-of-bits by chunk-of-bits, where the quantity of bits in that chunk at that node is the radix of the radix trie. When is 2, the radix trie is binary (i.e., compare that node's 1-bit portion of the key), which mini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patricia Trie Var
Patricia is a feminine given name of Latin language, Latin origin. Derived from the Latin word ''Patrician (ancient Rome), patrician'', meaning 'noble', it is the feminine form of the masculine given name Patrick (given name), Patrick. Another well-known variant is Patrice. According to the US Social Security Administration records, the use of the name for newborns peaked at #3 from 1937 to 1943 in the United States, after which it dropped in popularity, sliding to #745 in 2016.Popularity of a NameSocial Security Administration''ssa.gov'', accessed June 26, 2017 From 1928 to 1967, the name was ranked among the top 11 female names. In Portuguese and Spanish-speaking Latin-American countries, the name Patrícia/Patricia is common as well, pronounced in Portuguese and in Spanish. In Catalan language, Catalan and Portuguese language, Portuguese it is written Patrícia, while in Italy, Germany and Austria Patrizia is the form, pronounced in Italian and in German. In Polish langua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Art Of Computer Programming
''The Art of Computer Programming'' (''TAOCP'') is a comprehensive multi-volume monograph written by the computer scientist Donald Knuth presenting programming algorithms and their analysis. it consists of published volumes 1, 2, 3, 4A, and 4B, with more expected to be released in the future. The Volumes 1–5 are intended to represent the central core of computer programming for sequential machines; the subjects of Volumes 6 and 7 are important but more specialized. When Knuth began the project in 1962, he originally conceived of it as a single book with twelve chapters. The first three volumes of what was then expected to be a seven-volume set were published in 1968, 1969, and 1973. Work began in earnest on Volume 4 in 1973, but was suspended in 1977 for work on typesetting prompted by the second edition of Volume 2. Writing of the final copy of Volume 4A began in longhand in 2001, and the first online pre-fascicle, 2A, appeared later in 2001. The first published installment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Judy Array
In computer science, a Judy array is an early-2000s Hewlett-Packard hand-optimized implementation of a 256-ary radix tree that uses many situational node types to reduce latency from CPU cache-line fills.Alan Silverstein,Judy IV Shop Manual, 2002 As a compressed radix tree, a Judy array can store potentially sparse integer- or string-indexed data with comparatively low memory usage and low read latency, without relying on hashing or tree balancing, and without sacrificing in-order traversal. Per-operation latency scales as O(\log n)—as expected of a tree—and the leading constant factor is small enough that Judy arrays are suitable even to the peta-element range. When applicable, they can be faster than implementations of AVL trees, B-trees, hash tables, or skip lists from the same time period. History The Judy array was invented by Douglas Baskins over the years leading up to 2002 and named after his sister. Node types Broadly, tree nodes in Judy arrays fall into one of three ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deterministic Finite Automata
In the theory of computation, a branch of theoretical computer science, a deterministic finite automaton (DFA)—also known as deterministic finite acceptor (DFA), deterministic finite-state machine (DFSM), or deterministic finite-state automaton (DFSA)—is a finite-state machine that accepts or rejects a given string of symbols, by running through a state sequence uniquely determined by the string. ''Deterministic'' refers to the uniqueness of the computation run. In search of the simplest models to capture finite-state machines, Warren McCulloch and Walter Pitts were among the first researchers to introduce a concept similar to finite automata in 1943. The figure illustrates a deterministic finite automaton using a state diagram. In this example automaton, there are three states: S0, S1, and S2 (denoted graphically by circles). The automaton takes a finite sequence of 0s and 1s as input. For each state, there is a transition arrow leading out to a next state for both 0 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hash Trie
Hash, hashes, hash mark, or hashing may refer to: Substances * Hash (food), a coarse mixture of ingredients, often based on minced meat * Hash (stew), a pork and onion-based gravy found in South Carolina * Hash, a nickname for hashish, a cannabis product Hash mark * Hash mark (sports), a marking on hockey rinks and gridiron football fields * Hatch marks, hash marks or tick marks, a form of mathematical notation * Number sign (#), also known as the hash, hash mark, or (in American English) pound sign * Service stripe, a military and paramilitary decoration * Tally mark, a counting notation * Checkmate symbol in chess Computing * Hash function, an encoding of data into a small, fixed size; used in hash tables and cryptography ** Hash table In computer science, a hash table is a data structure that implements an associative array, also called a dictionary or simply map; an associative array is an abstract data type that maps Unique key, keys to Value (computer scienc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ternary Search Tries
Ternary (from Latin ''ternarius'') or trinary is an adjective meaning "composed of three items". It can refer to: Mathematics and logic * Ternary numeral system, a base-3 counting system ** Balanced ternary, a positional numeral system, useful for comparison logic * Ternary logic, a logic system with the values ''true'', ''false'', and some other value * Ternary plot or ternary graph, a plot that shows the ratios of three proportions * Ternary relation, a finitary relation in which the number of places in the relation is three * Ternary operation, an operation that takes three parameters * Ternary function, a function that takes three arguments Computing * Ternary signal, a signal that can assume three significant values * Ternary computer, a computer using a ternary numeral system * Ternary tree, a tree data structure in computer science **Ternary search tree, a ternary (three-way) tree data structure of strings * Ternary search, a computer science technique for finding the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deterministic Acyclic Finite State Automaton
In computer science, a deterministic acyclic finite state automaton (DAFSA),Jan Daciuk, Stoyan Mihov, Bruce Watson and Richard Watson (2000). Incremental construction of minimal acyclic finite state automata. Computational Linguistics 26(1):3-16. is a data structure that represents a set of strings, and allows for a query operation that tests whether a given string belongs to the set in time proportional to its length. Algorithms exist to construct and maintain such automata, while keeping them minimal. DAFSA is the rediscovery of a data structure called Directed Acyclic Word Graph (DAWG),Appel, Andrew; Jacobsen, Guy (1988). The World's Fastest Scrabble Program. Communications of the ACM, 31 (5): 572–578 although the same name had already been given to a different data structure which is related to suffix automaton.Anselm Blumer, Janet Blumer, Andrzej Ehrenfeucht, David Haussler, Ross M. McConnell (1983). Linear size finite automata for the set of all subwords of a word - an ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prefix Tree
In computer science, a trie (, ), also known as a digital tree or prefix tree, is a specialized search tree data structure used to store and retrieve strings from a dictionary or set. Unlike a binary search tree, nodes in a trie do not store their associated key. Instead, each node's ''position'' within the trie determines its associated key, with the connections between nodes defined by individual characters rather than the entire key. Tries are particularly effective for tasks such as autocomplete, spell checking, and IP routing, offering advantages over hash tables due to their prefix-based organization and lack of hash collisions. Every child node shares a common prefix with its parent node, and the root node represents the empty string. While basic trie implementations can be memory-intensive, various optimization techniques such as compression and bitwise representations have been developed to improve their efficiency. A notable optimization is the radix tree, which prov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hashtable
In computer science, a hash table is a data structure that implements an associative array, also called a dictionary or simply map; an associative array is an abstract data type that maps keys to values. A hash table uses a hash function to compute an ''index'', also called a ''hash code'', into an array of ''buckets'' or ''slots'', from which the desired value can be found. During lookup, the key is hashed and the resulting hash indicates where the corresponding value is stored. A map implemented by a hash table is called a hash map. Most hash table designs employ an imperfect hash function. Hash collisions, where the hash function generates the same index for more than one key, therefore typically must be accommodated in some way. In a well-dimensioned hash table, the average time complexity for each lookup is independent of the number of elements stored in the table. Many hash table designs also allow arbitrary insertions and deletions of key–value pairs, at amorti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HAT-trie
The HAT-trie is a type of radix trie that uses array nodes to collect individual key–value pairs under radix nodes and hash buckets into an associative array. Unlike a simple hash table, HAT-tries store key–value in an ordered collection. The original inventors are Nikolas Askitis and Ranjan Sinha. Askitis & Zobel showed that building and accessing the HAT-trie key/value collection is considerably faster than other sorted access methods and is comparable to the array hash which is an unsorted collection. This is due to the cache-friendly nature of the data structure which attempts to group access to data in time and space into the 64 byte cache line size of the modern CPU. Description A new HAT-trie starts out as a NULL pointer representing an empty node. The first added key allocates the smallest array node and copies into it the key/value pair, which becomes the first root of the trie. Each subsequent key/value pair is added to the initial array node until a maximum size ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hash Table
In computer science, a hash table is a data structure that implements an associative array, also called a dictionary or simply map; an associative array is an abstract data type that maps Unique key, keys to Value (computer science), values. A hash table uses a hash function to compute an ''index'', also called a ''hash code'', into an array of ''buckets'' or ''slots'', from which the desired value can be found. During lookup, the key is hashed and the resulting hash indicates where the corresponding value is stored. A map implemented by a hash table is called a hash map. Most hash table designs employ an Perfect hash function, imperfect hash function. Hash collision, Hash collisions, where the hash function generates the same index for more than one key, therefore typically must be accommodated in some way. In a well-dimensioned hash table, the average time complexity for each lookup is independent of the number of elements stored in the table. Many hash table designs also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serialization
In computing, serialization (or serialisation, also referred to as pickling in Python (programming language), Python) is the process of translating a data structure or object (computer science), object state into a format that can be stored (e.g. computer file, files in secondary storage devices, data buffers in primary storage devices) or transmitted (e.g. data streams over computer networks) and reconstructed later (possibly in a different computer environment). When the resulting series of bits is reread according to the serialization format, it can be used to create a semantically identical clone of the original object. For many complex objects, such as those that make extensive use of reference (computer science), references, this process is not straightforward. Serialization of object (computer science), objects does not include any of their associated Method (computer science), methods with which they were previously linked. This process of serializing an object is also c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
