Write a program to check weather a string accepted by grammar or not.

#include
#include
#include
int main()
{ char ch='y';
char ss[10];
int i, size;
clrscr();
cout<<"\nThe grammar is a*ab";
do
{
cout<<"\nenter the size";
cin>>size ;
cout<<"\nenter the string";
for(i=0;i {
cin>>ss[i];
}
if(ss[size-1]=='b' && ss[size-2]=='a')
{
for(i=0;i<=size-3;i++)
{
if(ss[i]=='a')
cout<<"\n"<<"Correct string:accepted by the grammar";
}
}
else
cout<<"\nincorrect string REJECTED!!!";
cout<<"\npress y to continue...";
cin>>ch;
}
while(ch=='y'|| ch=='Y');
getch();
return 0;
}

Write a program to convert NDFA to DFA.

#include«Iostream.h»
#include«conio.h»
#include«stdlib.h»
void main()
{
clrscr();
int n=10,A[10][2],init,final;
int temp[10][2];
cout««"Enter no of input";
cin»»n;
for(int i=0;i«n;i++)
{
cout««"Enter transition state for "««i+1««" node";
cout««"(Enter 11 for NULL)\n";
cout««"For a =";
cin»»A[i][1];
cout««"For b =";
cin»»A[i][2];

}
clrscr();
cout««"Entered NFA is\n";
cout««"STATE\t\t"««"a\t"««"b";
for(i=0;i«n;i++)
{ cout««"\nq"««i+1««"\t\t"««"q"««A[i][1]««"\t"««"q"««A[i][2];
}
cout««"\nEnter initial state: ";
cin»»init;
cout««"\nEnter final state: ";
cin»»final;
cout««"\n\n";
cout««" DFA is \n";
cout««"STATE\t\t"««"a\t"««"b\n";
cout««"q"««init««"\t\t"««"q"««A[init-1][1]««"\t"««"q"««A[init-1][2];
temp[init][1]=A[init][1];
temp[init][2]=A[init][2];
getch();
}

Write a program to convert Regular Expression to NFA.

#include
#include
#include
#include

void main()
{
clrscr();
char c[20];
int a[10][2];
int l,n=0,s=0,t;
cout<<"Enter the string:";
cin>>c;
l=strlen(c);
for(int f=0;f {
if(c[f]=='+')
{
s++;
}
}
n=s+1;
cout<<"Thus states="< for(int i=0;i {
t=1;
a[i][1]=t;
a[i][2]=(t-1);
t++;
if(i>=1)
{
a[i][2]=n-2;
if(i==2)
{
a[i][1]=n-1;
a[i][2]=n-1;
}
}
}
cout<<"\n\n\tNFA\n\n";
cout<<"state \t"<<"a\t"<<"b\t";
for(int j=0;j {
cout<<"\nq"< if(j==1)
{
cout<<",q"< }
cout<<"\t"<<"q"< }
getch();
}

Write a program to convert an infix expression to postfix expression.

#include
#include
#include
#include
#define operand(x)(x>='a'&&x<='z' || x>='A'&&x<='Z' || x>='0'&&x<='9')
char infix[30], postfix[30], stack[30];
int top,i=0;

void init()
{
top=-1;
}

void push(char x)
{
stack[++top]=x;
}

char pop()
{
return( stack[top--] );
}

int isp(char x)
{
int y;
y=(x=='('?6:x=='^'?4:x=='*'?2:x=='/'?2:x=='+'?1:x=='-'?1:x==')'?0:-1);
return y;
}

int icp(char x)
{
int y;
y=(x=='('?6:x=='^'?4:x=='*'?2:x=='/'?2:x=='+'?1:x=='-'?1:x==')'?4:-1);
return y;
}

void infixtopostfix()
{
int j,l=-1;
char x,y;
stack[++top]='\0';
for (j=0; j<=strlen(infix)-1; j++)
{
x=infix[j];
if (operand(x))
postfix[++l]=x;
else if (top=='\0')
push(x);
else
{
while (isp(stack[top]) >= icp(x) )
postfix[++l]=pop();
push(x);
}
}
while (top!='\0')
postfix[++l]=pop();
postfix[++l]='\0';
}

void main()
{
clrscr();
init();
cout<<"Enter an infix expression :\n";
gets(infix);

infixtopostfix();
cout<<"The resulting postfix expression is: "< getch();
}

Write program to convert an infix expression to prefix expression.

#include
#include
#include
#define operand(x)(x>='a'&&x<='z' || x>='A'&&x<'Z' || x<'0'&&x<='9')
char infix[30],prefix[30],stack[30];
int top,i=0;

void init()
{
top=-1;
}

void push(char x)
{
stack[++top]=x;
}

char pop()
{
return(stack[top--]);
}

int isp(char x)
{
int y;
y=(x=='('?6:x=='^'?4:x=='*'?2:x=='/'?1:x=='-'?1:x==')'?0:-1);
return y;
}
int icp(char x)
{
int y;
y=(x=='('?6:x=='^'?4:x=='*'?2:x=='/'?1:x=='-'?1:x==')'?4:-1);
return y;
}
void infixtoprefix()
{
int j,l=0;
char x,y;
stack[++top]='\0';
for (j=strlen(infix)-1;j>=0;j--)
{
x=infix[j];
if (operand(x))
prefix[l++]=x;
else
if(x=='(')
while((y=pop())!=')')
prefix[l++]=y;
else
{
while(isp(stack[top])>=icp(x))
prefix[l++]=pop();
push(x);
}
}

while(top>=0)
prefix[l++]=pop();
}

void main()
{
init();
printf("enter the infix expression :\n");
scanf("%s",infix);
infixtoprefix();
strrev(prefix);
printf("The resulting prefix expression is %s",prefix);
getch();
}

WAP that implements a JApplet that displays a simple label.

import java.awt.*;
import javax.swing.*;
import java.applet.*;
/*
Applet code is here...you should do urself..
*/
public class Class4 extends JApplet
{
public void init()
{
Container cp=getContentPane();
JLabel j=new JLabel("Hello");
cp.add(j);
cp.setVisible(true);
}

}

WAP to display 6 buttons on a panel using JFrame.

import java.awt.*;
import javax.swing.*;

class Class2 extends JFrame
{
public static void main(String s[])
{
JButton b1,b2,b3,b4,b5,b6;
JPanel p=new JPanel();
b1=new JButton("1");
b2=new JButton("2");
b3=new JButton("3");
b4=new JButton("4");
b5=new JButton("5");
b6=new JButton("6");
p.add(b1);
p.add(b2);
p.add(b3);
p.add(b4);
p.add(b5);
p.add(b6);
JFrame f=new JFrame("Demo");
f.getContentPane().add(p);
f.setSize(300,300);
f.setVisible(true);
}}