A method and system for pattern matching

Pattern matching can be achieved by considering only the position numbers of a source pattern and a target pattern within ordered sequences of possible source patterns and target patterns respectively. The position numbers of source patterns containing the target pattern form a number of groups. The number of source patterns within each group and the number of source patterns in the gaps between groups depend on the position of the target pattern within the source pattern, the length of the target pattern and the number of elements in the alphabet set. Each group also has a position number, its position within an ordered sequence of groups. The group position number of an input source pattern is compared to a series derived from the position number of the target pattern, the length of the target pattern and the number of elements in the alphabet set (9). If the group position number is a member of the series (10), then the source pattern contains the target pattern (11). Pattern matching can be performed on uncoded data or on arithmetic coded data.