Yaser Shokri Kalandaragh,
Abstract
Dealing with constraints is always very common in real-world implementation issues. Search algorithms for real problems are also no exception. Because of the constraints in search problems (named Constraint Satisfaction Problems (CSPs)), their main solving algorithm is presented in backtracking form. ...
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Dealing with constraints is always very common in real-world implementation issues. Search algorithms for real problems are also no exception. Because of the constraints in search problems (named Constraint Satisfaction Problems (CSPs)), their main solving algorithm is presented in backtracking form. The constraint propagation algorithm is an auxiliary tool to avoid facing constraint conditions as well as reducing search options. This algorithm has been presented in almost seven versions so far. In this paper, we have updated the third version of this algorithm, which is presented under the title of AC-3, from five aspects and have increased its capabilities. The most important feature of our proposed algorithm is its low time complexity. This feature has been made possible by two auxiliary criteria introduction for detecting more critical binary constraints. Faster investigation of critical constraints leads to early detection of dead-end in the search path and the search continues in this direction stops.
Anuj Kapoor
Abstract
Hash or B-Tree based composite indexes, are the two most commonly used techniques for searching and retrieving data from memory. Although these techniques have a serious memory limitation, that restricts \textit{freedom} to search by any combination of single key/data attribute, that comprises the composite ...
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Hash or B-Tree based composite indexes, are the two most commonly used techniques for searching and retrieving data from memory. Although these techniques have a serious memory limitation, that restricts \textit{freedom} to search by any combination of single key/data attribute, that comprises the composite search key, the techniques are still accepted considering the trade offs with better performance on insert and update operations. But when the data is semi-static, which does not change often, there is a need and scope for a better technique that provides the flexibility and freedom to efficiently search by any possible key, without creating any composite index. This paper explains such algorithmic technique along with its data structures.
