In computing, a one-pass algorithm is one which reads its input exactly once, in order, without unbounded buffering. A one-pass algorithm generally requires O(n) (see 'big O' notation) time and less than O(n) storage (typically O(1)), where n is the size of the input.
Contents
- Example problems solvable by one pass algorithms
- Example problems not solvable by one pass algorithms
- References
Basically one-pass algorithm operates as follows: (1) the object descriptions are processed serially; (2) the first object becomes the cluster representative of the first cluster; (3) each subsequent object is matched against all cluster representatives existing at its processing time; (4) a given object is assigned to one cluster (or more if overlap is allowed) according to some condition on the matching function; (5) when an object is assigned to a cluster the representative for that cluster is recomputed; (6) if an object fails a certain test it becomes the cluster representative of a new cluster
Example problems solvable by one-pass algorithms
Given any list as an input:
Given a list of numbers:
Given a list of symbols from an alphabet of k symbols, given in advance.
Example problems not solvable by one-pass algorithms
Given any list as an input:
Given a list of numbers: