Patent ID: 9720976
Date: 2017-08-01
CPC Classifications: G06F

Claim:
1. An appearance-map generating method of generating a plurality of appearance maps stored in a memory of a computer, the appearance-map generating method comprising: extracting, by the computer, a plurality of bi-gram character strings from a plurality of files; determining, by the computer, the rank of each bi-gram character string according to the number of times that the bi-gram character string appears in the files; generating, by the computer and for each higher-order bi-gram character string having a rank higher than a given rank, a non-divided appearance map having a size of 2 generating, by the computer and for each lower-order bi-gram character string having a rank lower than or equal to the given rank, n×m divided appearance maps each of which has a size of 2 storing, by the computer and into the memory, the non-divided appearance map of the size of 2 the n codes are obtained by dividing a code representing a first gram of the lower-order bi-gram character string into n parts, and the m codes are obtained by dividing a code representing a second gram of the lower-order bi-gram character string into m parts, where k, n, and m are natural numbers.