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  2. Iterator pattern - Wikipedia

    en.wikipedia.org/wiki/Iterator_pattern

    In object-oriented programming, the iterator pattern is a design pattern in which an iterator is used to traverse a container and access the container's elements. The iterator pattern decouples algorithms from containers; in some cases, algorithms are necessarily container-specific and thus cannot be decoupled.

  3. Associative array - Wikipedia

    en.wikipedia.org/wiki/Associative_array

    In computer science, an associative array, map, symbol table, or dictionary is an abstract data type that stores a collection of (key, value) pairs, such that each possible key appears at most once in the collection. In mathematical terms, an associative array is a function with finite domain. [1] It supports 'lookup', 'remove', and 'insert ...

  4. Pairing function - Wikipedia

    en.wikipedia.org/wiki/Pairing_function

    More generally, a pairing function on a set is a function that maps each pair of elements from into an element of , such that any two pairs of elements of are associated with different elements of , [5] [a] or a bijection from to .

  5. Raising and lowering indices - Wikipedia

    en.wikipedia.org/wiki/Raising_and_lowering_indices

    Raising and lowering is then done in coordinates. Given a vector with components , we can contract with the metric to obtain a covector: = and this is what we mean by lowering the index. Conversely, contracting a covector with the inverse metric gives a vector:

  6. Vector-valued function - Wikipedia

    en.wikipedia.org/wiki/Vector-valued_function

    In the linear case the function can be expressed in terms of matrices: =, where y is an n × 1 output vector, x is a k × 1 vector of inputs, and A is an n × k matrix of parameters. Closely related is the affine case (linear up to a translation ) where the function takes the form y = A x + b , {\displaystyle \mathbf {y} =A\mathbf {x} +\mathbf ...

  7. Bit array - Wikipedia

    en.wikipedia.org/wiki/Bit_array

    A bit array (also known as bitmask, [1] bit map, bit set, bit string, or bit vector) is an array data structure that compactly stores bits. It can be used to implement a simple set data structure. A bit array is effective at exploiting bit-level parallelism in hardware to perform operations quickly.

  8. R-tree - Wikipedia

    en.wikipedia.org/wiki/R-tree

    In quadratic split, the algorithm searches for the pair of rectangles that is the worst combination to have in the same node, and puts them as initial objects into the two new groups. It then searches for the entry which has the strongest preference for one of the groups (in terms of area increase) and assigns the object to this group until all ...

  9. Shortest path problem - Wikipedia

    en.wikipedia.org/wiki/Shortest_path_problem

    The all-pairs shortest path problem finds the shortest paths between every pair of vertices v, v' in the graph. The all-pairs shortest paths problem for unweighted directed graphs was introduced by Shimbel (1953) , who observed that it could be solved by a linear number of matrix multiplications that takes a total time of O ( V 4 ) .