toc/recognize.cpp at master · bikalpasharma/toc · GitHub

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
#include<stdio.h>
#include<conio.h>
#include<string.h>
#include<stdlib.h>
int main() {
	char s[20],c;
	int state=0,i=0;
	//clrscr();
	printf("\n Enter a string:");
	gets(s);

	while(s[i]!='\0') {
	switch(state) {
		case 0: c=s[i++];
				if(c=='a')
					state=1;
				else if(c=='b')
					state=2;
				else
					state=6;
				break;
		case 1: c=s[i++];
				if(c=='a')
					state=3;
				else if(c=='b')
					state=4;
				else
					state=6;
				break;
		case 2: c=s[i++];
				if(c=='a')
					state=6;
				else if(c=='b')
					state=2;
				else
					state=6;
				break;
		case 3: c=s[i++];
				if(c=='a')
					state=3;
				else if(c=='b')
					state=2;
				else
					state=6;
				break;
		case 4: c=s[i++];
				if(c=='a')
					state=6;
				else if(c=='b')
					state=5;
				else
					state=6;
				break;
		case 5: c=s[i++];
				if(c=='a')
					state=6;
				else if(c=='b')
					state=2;
				else
					state=6;
				break;
		case 6: printf("\n %s is not recognised.",s);
				exit(0);
	}
 	}

	if(state==1)
		printf("\n %s is accepted under rule 'a'",s);
	else if((state==2)||(state==4))
		printf("\n %s is accepted under rule 'a*b+'",s);
	else if(state==5)
		printf("\n %s is accepted under rule 'abb'",s);
	else if((state==6)||(state==3))
		printf("\n %s is not accepted under any rule!!",s);
	getch();
}