JP2835065B2 - String search method - Google Patents

Description

The present invention relates to a method of operating character string data in a data processing device such as a computer or a word processor.
In particular, the present invention relates to a method for searching for a certain character string.

[Related Art] In a conventional search method, a search character string and a search target character string are simply compared for each character to detect a match. The prior art will be described with reference to FIG. 5. To determine whether or not a character string 1 to be searched is included in the character string 1 to be searched, a search character string 2 (for example, X, Y , B) in the section of (A, B, C) of the character string 1 to be searched for, and if it is determined that they do not match, the next section is (B, C, C).
The same operation is performed in D). In this way, the sections (C, D, E), (D, E, A),... Of the searched character string 1 are compared in order from the beginning, and whether or not they match is determined. I do.

[Problems to be Solved by the Invention] According to the method described in the related art, the searched character string 1 is composed of a huge number of characters, and particularly when the searched character string 2 is located at the end of the searched character string 1. However, there is a problem that a search time for obtaining a conclusion of a match or a mismatch becomes long, and high-speed data processing cannot be performed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method capable of performing a character search in a short time with a simple operation, thereby enabling a high-speed information search of a system for editing Japanese sentences and a document management system.

[Means for Solving the Problems] In order to achieve the above object, in the character string search method of the present invention, a character string consisting of only the characters constituting the search character string, and having the same number of characters as the character string to be searched (This is referred to as a search character string), and each of the search character strings is formed into a logical OR sequence with the searched character string, and these adjacent logical OR sequences are sequentially shifted by one character. The logical sum is obtained, and the presence / absence, number, and position of the search character string are obtained from the result.

[Operation] The character string search method configured as described above is different from the character string to be searched, and forms a search character string corresponding to the number of characters constituting the search character string, and the character string to be searched and this search character string However, since the number of search character strings is far less than the number of characters constituting the search target character string, the number of accesses and time per access is reduced by the number of characters constituting the search target character string. The number of accesses and the time can be reduced as compared with the required conventional method. In particular, the longer the search target character string or the case where a plurality of character strings are present, the greater the difference between the number of accesses and the time.

[Embodiment] An embodiment will be described with reference to the drawings. The structure of a character string to be searched and a search character string are as shown by a character string 11 to be searched and a character string 12 to be searched in FIG. . First, as shown in FIG. 2, the number of valid characters of the searched character string 11 for each of the characters X, Y, and Z constituting the search character string 12, that is, in this embodiment, the search character string group 13 of the 16-character sentence Create Then, each of the search character strings 13 and the search target character string 11
Are subjected to a logical operation (AND) to obtain a code string group 14 (14a, 14b, 14c) as shown in FIG. Next, the adjacent code strings 14a to 14c of the code string group 14 are sequentially shifted one code at a time. That is, with reference to the code sequence 14a, the code sequence 14b is shifted by one code toward the head and the code sequence 14c is shifted by two codes toward the head, and are arranged as shown in FIG. The code sequences 14a to 14c thus shifted and arranged are subjected to a logical operation (AND) process, and are denoted by reference numeral 1 in FIG.
The code sequence as shown by 5 is finally obtained.

Then, it is checked whether or not this code string 15 includes a code 1 other than 0. When the code string 15 includes the code string as in the present embodiment, it is understood that the search character string 12 is included.
Also, by counting the number of codes 1 other than 0 in this code string 15, the search string 12
You can know the number of. Further, in the code string 15, the position of the search character string 12 can be known from the position of the code 1 other than 0. That is, when the code 1 is located at the nth position from the beginning (in this embodiment, at the 7th and 15th positions as shown in FIG. 4), the search character string 12 A position obtained by subtracting one less than the number N of constituent characters (in FIG. 4, since N = 3, it is a position obtained by subtracting N-1 = 2), that is, a position of n- (N-1). . Therefore, in FIG. 4, 7− (3-1) = 5,
The search character string 12 starts from the character position of 15− (3-1) = 13.

[Effect of the Invention] Since the present invention is a method configured as described above, it takes time to create a search character string, but when the search target character string is long or when there are a plurality of search character strings, CPU
This is a short time compared to the access time to the URL, and the search time is shortened accordingly. In addition, the search operation only needs to be performed for the creation of the search character string and the logical operation, and the number of operations can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a search character string and a search target character string according to the present invention;
FIG. 2 is an explanatory diagram showing a search character string as a search character string group, and FIG. 3 is an explanatory diagram showing a logical operation process of each of the search character string groups and a searched character string to form a code string group. FIG. 4 is an explanatory diagram of a logically processed code sequence that is shifted and arranged as a final code sequence, and FIG. 5 is a diagram for explaining the prior art. 11: Searched character string, 12: Search character string, 13: Search character string, 14: Code string group, 15: Code string

Claims (1)

(57) [Claims] 1. A character string search method for searching whether a character string to be searched for includes a character string to be searched, wherein each character constituting the character string to be searched has the same number of characters as the character string to be searched. A search character string is formed, a logical OR sequence of each of the search character strings and the search target character string is formed, and a logical OR of the logical OR sequence sequentially shifted by one character is obtained. A character string search method characterized by determining the presence, number, and position of columns.