|
Implicit Data Structure
In computer science, an implicit data structure or space-efficient data structure is a data structure that stores very little information other than the main or required data: a data structure that requires low overhead. They are called "implicit" because the position of the elements carries meaning and relationship between elements; this is contrasted with the use of pointers to give an ''explicit'' relationship between elements. Definitions of "low overhead" vary, but generally means constant overhead; in big O notation, ''O''(1) overhead. A less restrictive definition is a succinct data structure, which allows greater overhead. Definition An implicit data structure is one with constant space overhead (above the information-theoretic lower bound). Historically, defined an implicit data structure (and algorithms acting on one) as one "in which structural information is implicit in the way data are stored, rather than explicit in pointers." They are somewhat vague in the def ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Science
Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, applied disciplines (including the design and implementation of Computer architecture, hardware and Software engineering, software). Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of computational problem, problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and preventing security vulnerabilities. Computer graphics (computer science), Computer graphics and computational geometry address the generation of images. Programming language theory considers different ways to describe computational processes, and database theory concerns the management of re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field (computer Science)
In data hierarchy, a field (data field) is a Variable (computer science), variable in a record (computer science), record. A record, also known as a data structure, allows logically related data to be identified by a single name. Identifying related data as a single group is central to the construction of understandable computer programs. The individual fields in a record may be accessed by name, just like any variable in a computer program. Each field in a record has two components. One component is the field's data type, datatype Declaration (computer programming), declaration. The other component is the field's identifier. Memory fields Fields may be stored in random access memory (RAM). The following Pascal (programming language), Pascal record definition has three field identifiers: firstName, lastName, and age. The two name fields have a datatype of an Array (data structure), array of Character (computing), character. The age field has a datatype of integer. type PersonRec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Mauchly
John William Mauchly ( ; August 30, 1907 – January 8, 1980) was an American physicist who, along with J. Presper Eckert, designed ENIAC, the first general-purpose electronic digital computer, as well as EDVAC, BINAC and UNIVAC I, the first commercial computer made in the United States. Together, Mauchly and Eckert started the first computer company, the Eckert–Mauchly Computer Corporation (EMCC), which allowed them to further the development of fundamental computer concepts originally conceived by members of the 1945-46 ENIAC programming team, notably Jean Bartik and Kay McNulty, including subroutines, nesting, and the first low-level assembler. They also popularized the concept of the stored program, which was formalized in John von Neumann's widely-read '' First Draft of a Report on the EDVAC'' (1945) and disseminated through the Moore School Lectures (1946). These publications influenced an explosion of computer development around the world in the late 1940 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michaël Eytzinger
Michaël Eytzinger (Freiherr Michael von Aitzing, Aitzinger, Eyzinger, or Eitzing) (born ca. 1530 in Obereitzing - died 1598 in Bonn), was an Austrian nobleman, diplomat, historian, and publicist, who wrote and published several works, including a renowned volume that states the principles of a genealogical numbering system, called an Ahnentafel, that is still in use today. Eytzinger first published the Ahnentafel in 1590 in his ''Thesaurus principum hac aetate in Europa viventium'' (Cologne), 1590 (Google Books)(No Preview) in which he described and illustrated his new functional theory of numeration of ancestors by providing genealogies of thirty-four sovereign houses of Europe. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beap
A beap, or bi-parental heap, is a data structure for a set (or map, or multiset or multimap) that enables elements (or mappings) to be located, inserted, or deleted in sublinear time. In a beap, each element is stored in a node with up to two parents and up to two children, with the property that the value of a parent node is never greater than the value of either of its children. Beaps are implemented using an array containing only the values to be stored, with the parent-child relationships being determined implicitly by the array indices. (That is: beaps are an implicit data structure.) In that respect they are similar to binary heaps, which are usually implemented that way as well. However, their performance characteristics are different from heaps; in particular, a beap enables sublinear retrieval of arbitrary elements. The beap was introduced by Ian Munro and Hendra Suwanda. A related data structure is the Young tableau. Performance The height of the structure is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priority Queue
In computer science, a priority queue is an abstract data type similar to a regular queue (abstract data type), queue or stack (abstract data type), stack abstract data type. In a priority queue, each element has an associated ''priority'', which determines its order of service. Priority queue serves highest priority items first. Priority values have to be instances of an ordered data type, and higher priority can be given either to the lesser or to the greater values with respect to the given order relation. For example, in Java (programming language), Java standard library, ''PriorityQueues the least elements with respect to the order have the highest priority. This implementation detail is without much practical significance, since passing to the converse relation, opposite order relation turns the least values into the greatest, and vice versa. While priority queues are often implemented using Heap (data structure) , heaps, they are conceptually distinct. A priority queue can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Heap
A binary heap is a heap (data structure), heap data structure that takes the form of a binary tree. Binary heaps are a common way of implementing priority queues. The binary heap was introduced by J. W. J. Williams in 1964 as a data structure for implementing heapsort. A binary heap is defined as a binary tree with two additional constraints: *Shape property: a binary heap is a ''complete binary tree''; that is, all levels of the tree, except possibly the last one (deepest) are fully filled, and, if the last level of the tree is not complete, the nodes of that level are filled from left to right. *Heap property: the key stored in each node is either greater than or equal to (≥) or less than or equal to (≤) the keys in the node's children, according to some total order. Heaps where the parent key is greater than or equal to (≥) the child keys are called ''max-heaps''; those where it is less than or equal to (≤) are called ''min-heaps''. Efficient (that is, logarithmic tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complete Binary Tree
In computer science, a binary tree is a Tree (data structure), tree data structure in which each node has at most two child node, children, referred to as the ''left child'' and the ''right child''. That is, it is a m-ary tree, ''k''-ary tree with . A recursive definition using set theory is that a binary tree is a Triple (mathematics), triple , where ''L'' and ''R'' are binary trees or the empty set and ''S'' is a Singleton (mathematics), singleton (a single–element set) containing the root. From a graph theory perspective, binary trees as defined here are Arborescence (graph theory), arborescences. A binary tree may thus be also called a bifurcating arborescence, a term which appears in some early programming books before the modern computer science terminology prevailed. It is also possible to interpret a binary tree as an undirected graph, undirected, rather than directed graph, in which case a binary tree is an ordered tree, ordered, rooted tree. Some authors use rooted bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ahnentafel
An ''ahnentafel'' ( German for "ancestor table"; ) or ''ahnenreihe'' ("ancestor series"; ) is a genealogical numbering system for listing a person's direct ancestors in a fixed sequence of ascent. The subject (or proband) of the ahnentafel is listed as , the subject's father as and the mother as , the paternal grandparents as and and the maternal grandparents as and , and so on, back through the generations. Apart from , who can be male or female, all even-numbered persons are male, and all odd-numbered persons are female. In this schema, the number of any person's father is double the person's number, and a person's mother is double the person's number plus one. Using this definition of numeration, one can derive some basic information about individuals who are listed without additional research. This construct displays a person's genealogy compactly, without the need for a diagram such as a family tree. It is particularly useful in situations where one may be restricted t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancestry Chart
A family tree, also called a genealogy or a pedigree chart, is a chart representing family relationships in a conventional tree structure. More detailed family trees, used in medicine and social work, are known as genograms. Representations of family history Genealogical data can be represented in several formats, for example, as a pedigree or . Family trees are often presented with the oldest generations at the top of the tree and the younger generations at the bottom. An ancestry chart, which is a tree showing the ancestors of an individual and not all members of a family, will more closely resemble a tree in shape, being wider at the top than at the bottom. In some ancestry charts, an individual appears on the left and his or her ancestors appear to the right. Conversely, a descendant chart, which depicts all the descendants of an individual, will be narrowest at the top. Beyond these formats, some family trees might include all members of a particular surname (e.g., male ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perfect Binary Tree
In computer science, a binary tree is a tree data structure in which each node has at most two children, referred to as the ''left child'' and the ''right child''. That is, it is a ''k''-ary tree with . A recursive definition using set theory is that a binary tree is a triple , where ''L'' and ''R'' are binary trees or the empty set and ''S'' is a singleton (a single–element set) containing the root. From a graph theory perspective, binary trees as defined here are arborescences. A binary tree may thus be also called a bifurcating arborescence, a term which appears in some early programming books before the modern computer science terminology prevailed. It is also possible to interpret a binary tree as an undirected, rather than directed graph, in which case a binary tree is an ordered, rooted tree. Some authors use rooted binary tree instead of ''binary tree'' to emphasize the fact that the tree is rooted, but as defined above, a binary tree is always rooted. In mathema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Search Tree
In computer science, a binary search tree (BST), also called an ordered or sorted binary tree, is a Rooted tree, rooted binary tree data structure with the key of each internal node being greater than all the keys in the respective node's left subtree and less than the ones in its right subtree. The time complexity of operations on the binary search tree is Time complexity#Linear time, linear with respect to the height of the tree. Binary search trees allow Binary search algorithm, binary search for fast lookup, addition, and removal of data items. Since the nodes in a BST are laid out so that each comparison skips about half of the remaining tree, the lookup performance is proportional to that of binary logarithm. BSTs were devised in the 1960s for the problem of efficient storage of labeled data and are attributed to Conway Berners-Lee and David_Wheeler_(computer_scientist), David Wheeler. The performance of a binary search tree is dependent on the order of insertion of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
