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Shell Sort
Shellsort, also known as Shell sort or Shell's method, is an in-place comparison sort. It can be understood as either a generalization of sorting by exchange ( bubble sort) or sorting by insertion ( insertion sort). The method starts by sorting pairs of elements far apart from each other, then progressively reducing the gap between elements to be compared. By starting with far-apart elements, it can move some out-of-place elements into the position faster than a simple nearest-neighbor exchange. The running time of Shellsort is heavily dependent on the gap sequence it uses. For many practical variants, determining their time complexity remains an open problem. The algorithm was first published by Donald Shell in 1959, and has nothing to do with shells. Description Shellsort is an optimization of insertion sort that allows the exchange of items that are far apart. The idea is to arrange the list of elements so that, starting anywhere, taking every ''h''th element produces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorting Algorithm
In computer science, a sorting algorithm is an algorithm that puts elements of a List (computing), list into an Total order, order. The most frequently used orders are numerical order and lexicographical order, and either ascending or descending. Efficient sorting is important for optimizing the Algorithmic efficiency, efficiency of other algorithms (such as search algorithm, search and merge algorithm, merge algorithms) that require input data to be in sorted lists. Sorting is also often useful for Canonicalization, canonicalizing data and for producing human-readable output. Formally, the output of any sorting algorithm must satisfy two conditions: # The output is in monotonic order (each element is no smaller/larger than the previous element, according to the required order). # The output is a permutation (a reordering, yet retaining all of the original elements) of the input. Although some algorithms are designed for sequential access, the highest-performing algorithms assum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vaughan Ronald Pratt
Vaughan Pratt (born April 12, 1944) is a Professor Emeritus at Stanford University, who was an early pioneer in the field of computer science. Since 1969, Pratt has made several contributions to foundational areas such as search algorithms, sorting algorithms, and primality testing. More recently, his research has focused on formal modeling of concurrent systems and Chu spaces. Career Raised in Australia and educated at Knox Grammar School, where he was dux in 1961, Pratt attended Sydney University, where he completed his masters thesis in 1970, related to what is now known as natural language processing. He then went to the United States, where he completed a Ph.D. thesis at Stanford University in only 20 months under the supervision of advisor Donald Knuth. His thesis focused on analysis of the Shellsort sorting algorithm and sorting networks. Pratt was an assistant professor at MIT (1972 to 1976) and then associate professor (1976 to 1982). In 1974, working in collaborati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrew Yao
Andrew Chi-Chih Yao ( zh , c = 姚期智 , p = Yáo Qīzhì; born December 24, 1946) is a Chinese computer scientist, physicist, and computational theorist. He is currently a professor and the dean of Institute for Interdisciplinary Information Sciences (IIIS) at Tsinghua University. Yao used the minimax theorem to prove what is now known as Yao's principle. Yao was raised in Taiwan and graduated from National Taiwan University. He earned a master's degree and his PhD in physics from Harvard University, then earned a second doctorate in computer science from the University of Illinois Urbana-Champaign. Yao was a naturalized U.S. citizen, and worked for many years in the U.S. In 2015, together with Yang Chen-Ning, he renounced his U.S. citizenship and became an academician of the Chinese Academy of Sciences. Early life and education Yao was born in Shanghai, China, in 1946. His parents later moved to Hong Kong and then Taiwan, where Yao was raised. Yao graduated with his B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coin Problem
In mathematics, the coin problem (also referred to as the Frobenius coin problem or Frobenius problem, after the mathematician Ferdinand Georg Frobenius, Ferdinand Frobenius) is a mathematical problem that asks for the largest monetary amount that cannot be obtained using only coins of specified Denomination (currency), denominations. For example, the largest amount that cannot be obtained using only coins of 3 and 5 units is 7 units. The solution to this problem for a given set of coin denominations is called the Frobenius number of the set. The Frobenius number exists as long as the set of coin denominations is Coprime integers#Coprimality in sets, setwise coprime. There is an explicit formula for the Frobenius number when there are only two different coin denominations, x and y , where the greatest common divisor of these two numbers is 1: xy-x-y. If the number of coin denominations is three or more, no explicit formula is known. However, for any fixed number of coin deno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
