Efficient Parallel Algorithms for Tree Accumulations

Accumulations are higher-order operations on structured objects; they leave the shape of an object unchanged, but replace elements of that object with accumulated information about other elements. Upwards and downwards accumulations on trees are two such operations; they form the basis of many tree...

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Détails bibliographiques
Auteurs principaux: Gibbons, J, Cai, W, Skillicorn, D
Format: Journal article
Publié: 1994
Description
Résumé:Accumulations are higher-order operations on structured objects; they leave the shape of an object unchanged, but replace elements of that object with accumulated information about other elements. Upwards and downwards accumulations on trees are two such operations; they form the basis of many tree algorithms. We present two EREW PRAM algorithms for computing accumulations on trees taking O(\\log n) time on O(n/\\log n) processors, which is optimal.