Journal of the ACM

Backtrack search is often used to solve constraint satisfaction problems. A relationship involving the structure of the constraints is described that provides a bound on the backtracking required to advance deeper into the backtrack tree. This analysis ...

A parallel algorithm is presented that accepts as input a graph G and produces a maximal independent set of vertices in G. On a P-RAM without the concurrent write or concurrent read features, the algorithm executes in O((log n)⁴) time and uses O((n/(log ...

A hypergraph formalism is introduced to represent database schemata. In particular, a database schema B, described by one full join dependency and a set of functional dependencies, is represented by a (database) hypergraph H, containing both undirected ...

The problem of simulating a synchronous network by an asynchronous network is investigated. A new simulation technique, referred to as a synchronizer, which is a new, simple methodology for designing efficient distributed algorithms in asynchronous ...

A consensus protocol enables a system of n asynchronous processes, some of which are faulty, to reach agreement. There are two kinds of faulty processes: fail-stop processes that can only die and malicious processes that can also send false messages. ...

In a distributed system, one strategy for achieving mutual exclusion of groups of nodes without communication is to assign to each node a number of votes. Only a group with a majority of votes can execute the critical operations, and mutual exclusion is ...

The optimization problem for linear functions on finite languages is studied, and an (almost) complete characterization of those functions for which a primal and a dual greedy algorithm work well with respect to a canonically associated linear ...

It has been a challenge for mathematicians to confirm theoretically the extremely good performance of simplex-type algorithms for linear programming. In this paper the average number of steps performed by a simplex algorithm, the so-called self-dual ...

A simple model, AT, for nondeterministic machines is presented which is based on certain types of trees. A set of operations, Σ, is defined over AT and it is shown to be completely characterized by a set of inequations over Σ. AT is used to define the ...

The problem of recognizing the language L_n(L_{n, k}) of solvable Diophantine linear equations with n variables (and solutions from {O, … , k}ⁿ) is considered. The languages ∪_nϵN L_n, ∪_nϵN L_{n, l}, the knapsack problem, are NP-complete. The Ω(n² lower bound ...

Combinatorial techniques for extending lower bound results for decision trees to general types of queries are presented. Problems that are defined by simple inequalities between inputs, called order invariant problems, are considered. A decision tree is ...

An algorithm is presented that finds a min-cut linear arrangement of a tree in O(n log n) time. An extension of the algorithm determines the number of pebbles needed to play the black and white pebble game on a tree.