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Bridge And Torch Problem
The bridge and torch problem (also known as ''The Midnight Train'' and ''Dangerous crossing'') is a logic puzzle that deals with four people, a bridge and a torch. It is in the category of river crossing puzzles, where a number of objects must move across a river, with some constraints.Tricky Crossings , Ivars Peterson, ''Science News'', 164, #24 (December 13, 2003); accessed on line February 7, 2008. Story Four people come to a river in the night. There is a narrow bridge, and it can only hold two people at a time. They have one torch and, because it's night, the torch has to be used when crossing the bridge. Person A can cross the bridge in 1 minute, B in 2 minutes, C in 5 minutes, and D in 8 minutes. When two people cross the bridge together, they must move at the slower person's pace. The question is, ca ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Crossing Puzzle
A river crossing puzzle is a type of puzzle in which the object is to carry items from one river bank to another, usually in the fewest trips. The difficulty of the puzzle may arise from restrictions on which or how many items can be transported at the same time, or which or how many items may be safely left together.. The setting may vary cosmetically, for example, by replacing the river by a bridge. The earliest known river-crossing problems occur in the manuscript ''Propositiones ad Acuendos Juvenes'' (), traditionally said to be written by Alcuin. The earliest copies of this manuscript date from the 9th century; it contains three river-crossing problems, including the fox, goose, and bag of beans puzzle and the jealous husbands problem. Well-known river-crossing puzzles include: * The fox, goose, and bag of beans puzzle, in which a farmer must transport a fox, goose and bag of beans from one side of a river to another using a boat which can only hold one item in additi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridge And Torch Problem
The bridge and torch problem (also known as ''The Midnight Train'' and ''Dangerous crossing'') is a logic puzzle that deals with four people, a bridge and a torch. It is in the category of river crossing puzzles, where a number of objects must move across a river, with some constraints.Tricky Crossings , Ivars Peterson, ''Science News'', 164, #24 (December 13, 2003); accessed on line February 7, 2008. Story Four people come to a river in the night. There is a narrow bridge, and it can only hold two people at a time. They have one torch and, because it's night, the torch has to be used when crossing the bridge. Person A can cross the bridge in 1 minute, B in 2 minutes, C in 5 minutes, and D in 8 minutes. When two people cross the bridge together, they must move at the slower person's pace. The question is, ca ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Crossing Puzzle
A river crossing puzzle is a type of puzzle in which the object is to carry items from one river bank to another, usually in the fewest trips. The difficulty of the puzzle may arise from restrictions on which or how many items can be transported at the same time, or which or how many items may be safely left together.. The setting may vary cosmetically, for example, by replacing the river by a bridge. The earliest known river-crossing problems occur in the manuscript ''Propositiones ad Acuendos Juvenes'' (), traditionally said to be written by Alcuin. The earliest copies of this manuscript date from the 9th century; it contains three river-crossing problems, including the fox, goose, and bag of beans puzzle and the jealous husbands problem. Well-known river-crossing puzzles include: * The fox, goose, and bag of beans puzzle, in which a farmer must transport a fox, goose and bag of beans from one side of a river to another using a boat which can only hold one item in additi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logic Puzzle
A logic puzzle is a puzzle deriving from the mathematics, mathematical field of deductive reasoning, deduction. History The logic puzzle was first produced by Charles Lutwidge Dodgson, who is better known under his pen name Lewis Carroll, the author of ''Alice's Adventures in Wonderland''. In his book ''The Game of Logic'' he introduced a game to solve problems such as confirming the conclusion "Some greyhounds are not fat" from the statements "No fat creatures run well" and "Some greyhounds run well". Puzzles like this, where we are given a list of premises and asked what can be deduced from them, are known as syllogisms. Dodgson goes on to construct much more complex puzzles consisting of up to 8 premises. In the second half of the 20th century mathematician Raymond Smullyan, Raymond M. Smullyan continued and expanded the branch of logic puzzles with books such as ''The Lady or the Tiger?'', ''To Mock a Mockingbird'' and ''Alice in Puzzle-Land''. He popularized the "knights a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torch
A torch is a stick with combustible material at one end which can be used as a light source or to set something on fire. Torches have been used throughout history and are still used in processions, symbolic and religious events, and in juggling and entertainment. In some countries, notably the United Kingdom and Australia, "torch" in modern usage is also the term for a battery-operated portable light. Etymology From the Old French "''torche''" meaning "twisted thing", hence "torch formed of twisted tow dipped in wax", probably from Vulgar Latin *''torca'', alteration of Late Latin ''torqua'', variant of classical Latin ''torques'' "collar of twisted metal", from ''torquere'' "to twist". Torch construction Torch construction has varied through history depending on the torch's purpose. Torches were usually constructed of a wooden stave with one end wrapped in a material which was soaked in a flammable substance. In the United States, black bear bones may have been used. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graph Theory
In mathematics and computer science, graph theory is the study of ''graph (discrete mathematics), graphs'', which are mathematical structures used to model pairwise relations between objects. A graph in this context is made up of ''Vertex (graph theory), vertices'' (also called ''nodes'' or ''points'') which are connected by ''Glossary of graph theory terms#edge, edges'' (also called ''arcs'', ''links'' or ''lines''). A distinction is made between undirected graphs, where edges link two vertices symmetrically, and directed graphs, where edges link two vertices asymmetrically. Graphs are one of the principal objects of study in discrete mathematics. Definitions Definitions in graph theory vary. The following are some of the more basic ways of defining graphs and related mathematical structures. Graph In one restricted but very common sense of the term, a graph is an ordered pair G=(V,E) comprising: * V, a Set (mathematics), set of vertices (also called nodes or points); * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Search Problem
In computational complexity theory and computability theory, a search problem is a computational problem of finding an ''admissible'' answer for a given input value, provided that such an answer exists. In fact, a search problem is specified by a binary relation where if and only if "'' is an admissible answer given ''". Search problems frequently occur in graph theory and combinatorial optimization, e.g. searching for matchings, optional cliques, and stable sets in a given undirected graph. An algorithm is said to solve a search problem if, for every input value , it returns an admissible answer for when such an answer exists; otherwise, it returns any appropriate output, e.g. "not found" for with no such answer. Definition PlanetMath defines the problem as follows: If R is a binary relation such that \operatorname(R)\subseteq\Gamma^ and T is a Turing machine, then T calculates f if: * If x is such that there is some y such that R(x,y) then T accepts x with output z suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
From Bacteria To Bach And Back
''From Bacteria to Bach and Back: The Evolution of Minds'' is a 2017 book about the origin of human consciousness by the philosopher Daniel Dennett, in which the author makes a case for a materialist theory of mind, arguing that consciousness is no more mysterious than gravity. Drawing on ideas from René Descartes and Charles Darwin, Dennett writes that: :'... natural systems can create "competence without comprehension"—that is, situations in which sophisticated actions occur without the individual or machine involved understanding the reasons for the actions taken.' and that: :'a comprehending mind could in fact have arisen from a mindless process of natural selection. ...' Critical reception Physician Harriet Hall reviewing the book for ''Skeptical Inquirer'' magazine, said that "Dennett is always worth reading, and this latest book distills his current thinking and all he has learned over the years". He discusses many "conundrums with facts and arguments from evolution an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combinatorial Optimization
Combinatorial optimization is a subfield of mathematical optimization that consists of finding an optimal object from a finite set of objects, where the set of feasible solutions is discrete or can be reduced to a discrete set. Typical combinatorial optimization problems are the travelling salesman problem ("TSP"), the minimum spanning tree problem ("MST"), and the knapsack problem. In many such problems, such as the ones previously mentioned, exhaustive search is not tractable, and so specialized algorithms that quickly rule out large parts of the search space or approximation algorithms must be resorted to instead. Combinatorial optimization is related to operations research, algorithm theory, and computational complexity theory. It has important applications in several fields, including artificial intelligence, machine learning, auction theory, software engineering, VLSI, applied mathematics and theoretical computer science. Applications Basic applications of combina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
