A new linear time algorithm for indexed full-text search is presented.
The algorithm uses a modified factor oracle as an index database.
A factor oracle is an acyclic automaton made from an input text,
and it recognizes all of substrings in the text.
It can be built in time proportional to the text length,
and it is more space economical and easy to implement
comparing similar machineries such as
suffix-tree or suffix-automaton.
On the other hand, it has a problem
that it may accept strings not in the text;
thus, we cannot use factor oracles for indexed searching directly.
We solve this problem and
realize full-text-indexing using a modified factor oracle.
The search algorithm runs in time proportional to the length of pattern,
and it is again easy to implement.
(This report is written in Japanese;
an English version will be available by September.)