programming-for-dummies

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Sequential Text Search
Sequential Text Search
The simplest text searching algorithm is the brute force sequential search,
which simply examines every character. To look for the string gag in text, the
brute force sequential search examines the text character by character. The
moment it finds the letter g, it checks to see whether the next letter is a and
so on. To find anything, this search algorithm must exhaustively examine
every character, as shown in Figure 3-1.
In searching for the string GAG, a brute force search starts with the first character
and finds a matching G character. Next, it checks whether the next two
characters are an A and a G.
Searching for the string GAG
G
A T A G
A
G
A
T
G
G A T A G A G A
T
GA
G A T A G A G A
T
GAT (Fail)
G
A T A G A G A
T
Figure 3-1:
Sequential
search
examines
every
character.
Check second character for G
G A T A G A G A
Check third character for G
T