FazBrowse GitHub Viewer
|
Trending
|
URL:
|
Home
Tools:
[Download Repo ZIP]
[View Raw Code]
[Original HTTPS Page]
Java/Others/StringMatchFiniteAutomata.java at dev · primary-code-test/Java · GitHub
primary-code-test
Java
Repository navigation
Code
Pull requests
Actions
Projects
Security and quality
Insights
Expand file tree
Breadcrumbs
Java
/
Others
/
StringMatchFiniteAutomata.java
Copy path
More file actions
More file actions
Latest commit
History
History
History
81 lines (59 loc) · 1.86 KB
Breadcrumbs
Java
/
Others
/
StringMatchFiniteAutomata.java
Copy path
File metadata and controls
81 lines (59 loc) · 1.86 KB
Raw
Copy raw file
Download raw file
Open symbols panel
Edit and raw actions
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
/** @author Prateek Kumar Oraon (https://github.com/prateekKrOraon) */
import
java
.
util
.
Scanner
;
// An implementaion of string matching using finite automata
public
class
StringMatchFiniteAutomata
{
public
static
final
int
CHARS
=
256
;
public
static
int
[][]
FA
;
public
static
Scanner
scanner
=
null
;
public
static
void
main
(
String
[]
args
) {
scanner
=
new
Scanner
(
System
.
in
);
System
.
out
.
println
(
"Enter String"
);
String
text
=
scanner
.
nextLine
();
System
.
out
.
println
(
"Enter pattern"
);
String
pat
=
scanner
.
nextLine
();
searchPat
(
text
,
pat
);
scanner
.
close
();
}
public
static
void
searchPat
(
String
text
,
String
pat
) {
int
m
=
pat
.
length
();
int
n
=
text
.
length
();
FA
=
new
int
[
m
+
1
][
CHARS
];
computeFA
(
pat
,
m
,
FA
);
int
state
=
0
;
for
(
int
i
=
0
;
i
<
n
;
i
++) {
state
=
FA
[
state
][
text
.
charAt
(
i
)];
if
(
state
==
m
) {
System
.
out
.
println
(
"Pattern found at index "
+ (
i
-
m
+
1
));
}
}
}
// Computes finite automata for the partern
public
static
void
computeFA
(
String
pat
,
int
m
,
int
[][]
FA
) {
for
(
int
state
=
0
;
state
<=
m
; ++
state
) {
for
(
int
x
=
0
;
x
<
CHARS
; ++
x
) {
FA
[
state
][
x
] =
getNextState
(
pat
,
m
,
state
,
x
);
}
}
}
public
static
int
getNextState
(
String
pat
,
int
m
,
int
state
,
int
x
) {
// if current state is less than length of pattern
// and input character of pattern matches the character in the alphabet
// then automata goes to next state
if
(
state
<
m
&&
x
==
pat
.
charAt
(
state
)) {
return
state
+
1
;
}
for
(
int
ns
=
state
;
ns
>
0
;
ns
--) {
if
(
pat
.
charAt
(
ns
-
1
) ==
x
) {
for
(
int
i
=
0
;
i
<
ns
-
1
;
i
++) {
if
(
pat
.
charAt
(
i
) !=
pat
.
charAt
(
state
-
ns
+
i
+
1
)) {
break
;
}
if
(
i
==
ns
-
1
) {
return
ns
;
}
}
}
}
return
0
;
}
}
Back
|
FazBrowse Home
|
New Git URL