Dcn code and output

-1- VERTICAL REDUNDANCY CHECK

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
void receiver();
void sender();
int i,j,data[20];
void main()
{
int ans;
clrscr();
printf("nn*********************** VERTICAL REDUNDANCY
CHECK ***********************nn");
while(1)
{
printf("n--------------------------------------------------------------------------n
");
printf("ttttMAIN MENU");
printf("n--------------------------------------------------------------------------n
n");
printf("Choice No. Choice Name.nn");
printf(" 1. Sender's Sidenn 2. Receiver's Sidenn 3.
ExitnnnEnter Your Choice : ");
scanf("%d",&ans);
switch(ans)
{
case 1:
printf("n-----------------------------------------------------------
-------------n");
printf("ttt Sender's Side");
printf("n-----------------------------------------------------------
--------------n");
sender();
break;
case 2:
printf("n-----------------------------------------------------------
--------------n");
printf("ttt Receiver's Side");
printf("n-----------------------------------------------------------
--------------n");
receiver();
break;
case 3:
exit(1);
default:

1

printf("nnINVALID ENTRY!!!");
}
}
}

void receiver()
{
int sum=0;
printf("nEnter the number of bits you want (Max 20) : ");
scanf("%d",&j);
printf("nnEnter %d bits : ",j);
for(i=0;i<j;i++)
{
printf("nn %d bit: ",i+1);
scanf("%d",&data[i]);
if((data[i]!=0) && (data[i]!=1))
{
printf("nInvalid Bit......Enter only (1's and 0's) ");
i--;
}
}
for(i=0;i<j;i++)
{
sum=sum+data[i];
}
printf("n-------------------------------------------------------------------------n");
printf("ttttOutput");
printf("n-------------------------------------------------------------------------");
printf("nnThe Number of 1's in the message is: %d",sum);
if(sum%2==0)
{
printf("nnThere is no ERROR in the message.");
}
else
{
printf("nnThere is ERROR in the message.");
}
}

void sender()
{
int sum=0;
printf("nEnter the number of bits you want (Max 20) : ");
scanf("%d",&j);
printf("nEnter %d bits : ",j);
for(i=0;i<j;i++)

2

{
printf("nn %d bit: ",i+1);
if((data[i]!=0) && (data[i]!=1))
{
printf("nInvalid bit......Enter only (1's and 0's) ");
i--;
}
}
for(i=0;i<j;i++)
{
sum=sum+data[i];
}
printf("n-------------------------------------------------------------------------n");
printf("ttttOutput");
printf("n-------------------------------------------------------------------------");
printf("nnThe Message sent was : ");
for(i=0;i<j;i++)
{
printf("%d",data[i]);
}
if(sum%2!=0)
{
printf("nnParity Bit is : 1");
data[j]=1;
printf("nnThe Message after appending parity bit was : ");
for(i=0;i<=j;i++)
{
}
}
else
{
printf("nnParity Bit is : 0");
data[j]=0;
printf("nnThe Message after appending parity bit was : ");
for(i=0;i<=j;i++)
{
}
}
}

3

OUTPUT:-

****************** VERTICAL REDUNDANCY CHECK *******************

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-

Choice No. Choice Name.

1. Sender's Side

2. Receiver's Side

3. Exit

Enter Your Choice : 1

-----------------------------------------------------------------------------------------------------------
-
Sender's Side
-----------------------------------------------------------------------------------------------------------
-

Enter the number of bits you want (Max 20) : 5

Enter 5 bits :

1 bit: 1

2 bit: 0

3 bit: 1

4 bit: 0

5 bit: 1

-----------------------------------------------------------------------------------------------------------
-

4

Output
-----------------------------------------------------------------------------------------------------------
-

The Message sent was : 10101

Parity Bit is : 1

The Message after appending parity bit was : 101011
-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Side

2. Receiver's Side

3. Exit


-----------------------------------------------------------------------------------------------------------
-
Receiver's Side
-----------------------------------------------------------------------------------------------------------
-

Enter the number of bits you want (Max 20) : 4

Enter 4 bits :

1 bit: 1

2 bit: 0

3 bit: 2

Invalid Bit......Enter only (1's and 0's)

5

3 bit: 0

4 bit: 1

-----------------------------------------------------------------------------------------------------------
-
Output
-----------------------------------------------------------------------------------------------------------
-

The Number of 1's in the message is: 2
There is no ERROR in the message.
-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Side

2. Receiver's Side

3. Exit


6

-2- LONGITUDINAL REDUNDANCY CHECK

#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
int a[10][10];
int count,j,i,n,m;
void sender();
void receiver();
void main()
{
int ans;
clrscr();
printf("nn*********************** LONGITUDINAL REDUNDANCY
CHECK ***********************nn");
while(1)
{
printf("n--------------------------------------------------------------------------n
");
printf("n--------------------------------------------------------------------------n
n");
printf(" 1. Sender's Sitenn 2. Receiver's Sitenn 3.
scanf("%d",&ans);
switch(ans)
{
case 1:
printf("n-----------------------------------------------------------
--------------n");

7

printf("ttt Sender's Site");
printf("n-----------------------------------------------------------
--------------n");
sender();
break;
case 2:
printf("n-----------------------------------------------------------
--------------n");
printf("ttt Receiver's Site");
printf("n-----------------------------------------------------------
--------------n");
receiver();
break;

case 3:
exit(1);
default:
}
}
}

void sender()
{
printf("Enter the number of rows and columns max(5) : ");
scanf("%d%d",&m,&n);
printf("nEnter %d rows and %d columns : n",m,n);
for(i=1;i<=m;i++)
{
printf("nEnter %d row %d bits : ",i,n);
for(j=1;j<=n;j++)
{
scanf("%d",&a[i][j]);
if((a[i][j]!=0)&&(a[i][j]!=1))
{
printf("nnInvalid Bit......Enter another bit(Only 1's
and 0's)!!!");
j--;
}
}
}
for(i=1;i<=n;i++)
{
for(j=1;j<=m;j++)
{
if(a[j][i]==1)

8

{
count++;
}
}
if(count%2==0)
{
a[j][i]=0;
count=0;
}
else
{
a[j][i]=1;
count=0;
}
}
printf("n--------------------------------------------- Output
-----------------------------------n");
printf("nThe parity row is : n");
i=m+1;
for(j=1;j<=n;j++)
{
printf("%dt",a[i][j]);
}
printf("nnThe Message after appending : n");
for(i=1;i<=m+1;i++)
{
for(j=1;j<=n;j++)
{
printf("%dt",a[i][j]);
}
printf("nn");
}
}

void receiver()
{
int count1=0;
printf("Enter the number of rows and columns max(5) : ");
scanf("%d%d",&m,&n);
printf("nEnter %d rows and %d columns : ",m,n);
for(i=1;i<=m;i++)
{
printf("nnEnter %d row %d bits : ",i,n);
for(j=1;j<=n;j++)
{
scanf("%d",&a[i][j]);

9

if((a[i][j]!=0)&&(a[i][j]!=1))
{
printf("nnInvalid Bit......Enter another bit(Only 1's
and 0's)!!!");
j--;
}
}
}
printf("n-------------------------------------------- Output
----------------------------------------n");
for(i=1;i<=n;i++)
{
for(j=1;j<=m;j++)
{
if(a[j][i]==1)
{
count++;
}
}
if(count%2==0)
{
count1++;
count=0;

}
else
{
count=0;
}
}
if(count1==n)
printf("nData is correctly received...n");
else
printf("nData is not correctly received...n");

}

10

OUTPUT:-

***************** LONGITUDINAL REDUNDANCY CHECK ***************

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


-----------------------------------------------------------------------------------------------------------
-
Sender's Site
-----------------------------------------------------------------------------------------------------------
-
Enter the number of rows and columns max(5) : 2 3

Enter 2 rows and 3 columns :

Enter 1 row 3 bits : 1 0 0


11

----------------------------------------------- Output --------------------------------------------------

The parity row is :
0 0 1

The Message after appending :
1 0 0

1 0 1

0 0 1

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


-----------------------------------------------------------------------------------------------------------
-
Receiver's Site
-----------------------------------------------------------------------------------------------------------
-

Enter the number of rows and columns max(5) : 2 3

Enter 2 rows and 3 columns :


12


------------------------------------------------ Output -------------------------------------------------

Data is not correctly received...

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


13

-3- CYCLIC REDUNDANCY CHECK

#include<stdlib.h>
#include<conio.h>
#include<stdio.h>

void receiver();
void sender();

int i,j,n,g,a1,a[20]={0},d[20]={0},b[20],p[20],s,cnt;

void main()
{
int choice;
clrscr();
printf("*********************** CYCLIC REDUNCDANCY CHECK
**********************n");
while(1)
{
printf("nn--------------------------------------------------------------------------
n");

14

printf("n--------------------------------------------------------------------------n
n");
scanf("%d",&choice);

switch(choice)
{
case 1:
printf("n--------------------------- Sender's Site
----------------------------");
sender();
break;

case 2:
printf("n------------------------- Receiver's Site
---------------");
receiver();
break;

case 3:
exit(1);
}
}
}

void sender()
{
printf("nnEnter total number of data bits : ");
scanf("%d",&n);
printf("nEnter %d data bits : nn",n);
for(i=0;i<n;i++)
{
printf("nEnter bit %d: ",i+1);
scanf("%d",&a[i]);
if((a[i]!=1)&& (a[i]!=0))
{
printf("nInvalid Entry...Enter only 1's & 0's!!!n");
i--;
}
}
printf("nEnter size of Key (! >databits) : ");
scanf("%d",&g);

15

if(g>n)
{
printf("nInvalid Entry...Enter value less than databit!!!n");
printf("nEnter size of Key (! >databits): ");
scanf("%d",&g);
}
do
{
printf("nEnter Key values : nn");
for(j=0;j<g;j++)
{
printf("nEnter key bit %d : ",j+1);
scanf("%d",&d[j]);
if((d[j]!=1)&& (d[j]!=0))
{
j--;
}
}
}while(d[0]!=1);
printf("n------------------------------------------------------------------n");
printf("ttOutput ");
printf("n------------------------------------------------------------------n");
a1=n+(g-1);
printf("nnThe Message : t");
for(i=0;i<a1;++i)
{
if(i<a1)
{
p[i]=a[i];
}
else
{
p[i]=0;
}
}
for(i=0;i<a1;++i)
{
printf("%d",p[i]);
}
printf("nnThe Divisor : t");
for(j=0;j<g;j++)
{
printf("%d",d[j]);
}
printf("nnIntermediate CRC : ");

16

for(i=0;i<n;++i)
{
if(a[i]==0)
{
printf(" ");
for(j=i;j<g+i;++j)
{
a[j] = a[j]^0;
printf("%d",a[j]);
}
}
else
{
printf(" ");
a[i] = a[i]^d[0];
a[i+1]=a[i+1]^d[1];
a[i+2]=a[i+2]^d[2];
a[i+3]=a[i+3]^d[3];
printf("%d%d%d",a[i],a[i+1],a[i+2]);
printf(" ");
}
}
printf("nnThe Final CRC Bit is : t");
for(i=n;i<a1;++i)
{
printf("%d",a[i]);
}
s=n+a1;
for(i=n;i<s;i++)
{
p[i]=a[i];
}
printf("n");
printf("nThe Message transmitted is : ");
for(i=0;i<a1;i++)
{
printf("%d",p[i]);
}
}
void receiver()
{
printf("nnEnter total number of data bits: ");
scanf("%d",&n);
printf("nEnter %d data bits : nn",n);
for(i=0;i<n;i++)
{

17

printf("nEnter bit %d : ",i+1);
scanf("%d",&a[i]);
if((a[i]!=1)&& (a[i]!=0))
{
i--;
}
}
scanf("%d",&g);
if(g>n)
{
printf("nInvalid Entry...Enter value less than databit!!!n");
scanf("%d",&g);
}
do
{
printf("nEnter Key values : nn");
for(j=0;j<g;j++)
{
printf("nEnter key bit %d : ",j+1);
scanf("%d",&d[j]);
if((d[j]!=1)&& (d[j]!=0))
{
j--;
}
}
}while(d[0]!=1);
printf("n-------------------------------------------------------------------------------n");
printf("ttOutput");
printf("n--------------------------------------------------------------------------------n");
printf("nnThe Message : t");
for(i=0;i<n;++i)
{
p[i]=a[i];
}
for(i=0;i<n;i++)
{
printf("%d",p[i]);
}
printf("nnThe Divisor : t");
for(j=0;j<g;j++)
{
printf("%d",d[j]);

18

}
a1=n+(g-1);
printf("nnCRC's : ");
for(i=0;i<n;i++)
{
if(a[i]==0)
{
printf(" ");
for(j=i;j<g+i;j++)
{
a[j] = a[j]^0;
printf("%d",a[j]);
}
}
else
{
printf(" ");
a[i] = a[i]^d[0];
a[i+1]=a[i+1]^d[1];
a[i+2]=a[i+2]^d[2];
a[i+3]=a[i+3]^d[3];
printf("%d%d%d",a[i],a[i+1],a[i+2]);
printf(" ");
}
}
printf("nnThe Final CRC is : ");
for(i=n;i<a1;++i)
{
printf("%d",a[i]);
}
s=n+a1;
cnt=0;
for(i=n;i<s;i++)
{
p[i]=a[i];
if(p[i]==1)
{
cnt++;
}
}
printf("n");
if(cnt==0)
{
printf("nnThe Message is received correctly");
}
else

19

{
printf("nnThe Message is not received correctly");
}
}

Output:-

********************** CYCLIC REDUNCDANCY CHECK ****************

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


----------------------------------------------- Sender's Site
-------------------------------------------

20

Enter total number of data bits : 5

Enter 5 data bits :

Enter bit 1: 1

Enter bit 2: 0

Enter bit 3: 1

Enter bit 4: 1

Enter bit 5: 0

Enter size of Key (! >databits) : 3

Enter Key values :

Enter key bit 1 : 1

Enter key bit 2 : 1

Enter key bit 3 : 0

-----------------------------------------------------------------------------------------------------------
-
Output
-----------------------------------------------------------------------------------------------------------
-

The Message : 1011000

The Divisor : 110

Intermediate CRC : 011 001 010 010 010

The Final CRC Bit is : 10

The Message transmitted is : 1011010

-----------------------------------------------------------------------------------------------------------
-

21

MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


---------------------------------------------- Receiver's Site -----------------------------------------

Enter total number of data bits: 5

Enter 5 data bits :

Enter bit 1 : 1

Enter bit 2 : 1

Enter bit 3 : 0

Enter bit 4 : 1

Enter bit 5 : 1

Enter size of Key (! >databits): 3

Enter Key values :

Enter key bit 1 : 1

Enter key bit 2 : 0

Enter key bit 3 : 1

-----------------------------------------------------------------------------------------------------------
-
Output
-----------------------------------------------------------------------------------------------------------
-

22

The Message : 11011

The Divisor : 101

CRC's : 011 010 000 000 000

The Final CRC is : 00

The Message is received correctly

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


-4- CHECKSUM

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
int sum(int,int);
int sum1(int,int,int);
void sender();
void receiver();
int a[8],b[8],r[8],c[8],r1[8];

23

static int carry=0;
int n,i,count=0;
void main()
{
int choice;
clrscr();
printf("n*********************************** CHECKSUM
*********************************n");
while(1)
{
printf("nn--------------------------------------------------------------------------
n");
printf("n--------------------------------------------------------------------------n
n");
switch(choice)
{
case 1:
printf("-------------------------------------------------------------
-----------n");
printf("ntt Sender's Site ");
printf("n-----------------------------------------------------------
-------------n");
sender();
break;

case 2:
printf("-------------------------------------------------------------
-----------n");
printf("nttReceiver's Site ");
printf("n-----------------------------------------------------------
-------------n");
receiver();
break;

case 3:
exit(1);

default:
printf("nnINVALID ENTRY");
}
}

24

}

void sender()
{
printf("nEnter the total number of bits : ");
scanf("%d",&n);
printf("nEnter %d bits of Data 1 : nn",n);
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);
if(a[i]!=0 && a[i]!=1)
{
printf("nnInvalid Bit......Enter another value(only 1's and
0's)!!!!!");
i--;
}
}
printf("n------------------------------------------------------------------n");
for(i=0;i<n;i++)
{
scanf("%d",&b[i]);
if(b[i]!=0 && b[i]!=1)
{
0's)!!!!!");
i--;
}
}
printf("n-----------------------------------------------------------------------------n");
printf("nttOutput");
printf("n-----------------------------------------------------------------------------n");
printf("nnData 1:ttt ");
for(i=0;i<n;i++)
{
printf("%d",a[i]);
}
for(i=0;i<n;i++)
{
printf("%d",b[i]);
}
for(i=n;i>=0;i--)
{

25

r[i]=sum(a[i],b[i]);
}
printf("nnResult :tt ");
for(i=0;i<n;i++)
{
printf("%d",r[i]);
}
for(i=0;i<n;i++)
{
if (r[i]==0)
{
r[i]=1;
}
else
{
r[i]=0;
}
}
printf("nn1's Compliment of Result :");
for(i=0;i<n;i++)
{
printf("%d",r[i]);
}
}

int sum(int x,int y)
{
if(x==0 && y==0 && carry==0)
{
carry=0;
return 0;
}
else if(x==0 && y==0 && carry==1)
{
carry=0;
return 1;
}
else if(x==0 && y==1 && carry==0)
{
carry=0;
return 1;
}
else if(x==0 && y==1 && carry==1)
{
carry=1;
return 0;

26

}
else if(x==1 && y==0 && carry==0)
{
carry=0;
return 1;
}
else if(x==1 && y==0 && carry==1)
{
carry=1;
return 0;
}
else if(x==1 && y==1 && carry==0)
{
carry=1;
return 0;
}
else if(x==1 && y==1 && carry==1)
{
carry=1;
return 1;
}
else
return(1);
}

void receiver()
{
printf("nEnter the total number of bits : ");
scanf("%d",&n);
for(i=0;i<n;i++)
{
scanf("%d",&a[i]);
if(a[i]!=0 && a[i]!=1)
{
0's)!!!!!");
i--;
}
}
printf("n------------------------------------------------------------------n");
for(i=0;i<n;i++)
{

27

scanf("%d",&b[i]);
if(b[i]!=0 && b[i]!=1)
{
0's)!!!!!");
i--;
}
}
printf("n------------------------------------------------------------------n");
printf("nEnter %d bits of Checksum : nn",n);
for(i=0;i<n;i++)
{
scanf("%d",&c[i]);
if(c[i]!=0 && c[i]!=1)
{
0's)!!!!!");
i--;
}
}
printf("n----------------------------------------------------------------------------------");
printf("nttOutput");
printf("n----------------------------------------------------------------------------------");
for(i=0;i<n;i++)
{
printf("%d",a[i]);
}
for(i=0;i<n;i++)
{
printf("%d",b[i]);
}
printf("nnChecksum:tt ");
for(i=0;i<n;i++)
{
printf("%d",c[i]);
}
for(i=n;i>=0;i--)
{
r1[i]=sum1(a[i],b[i],c[i]);
}
printf("nnResult :tt ");
for(i=0;i<n;i++)
{

28

printf("%d",r1[i]);
}
for(i=0;i<n;i++)
{
if (r1[i]==0)
{
r1[i]=1;
}
else
{
r1[i]=0;
}
}
printf("nn1's Compliment of Result :");
for(i=0;i<n;i++)
{
printf("%d",r1[i]);
}
for(i=0;i<n;i++)
{
if(r1[i]==0)
{
count=count+1;
}
}
if(count==n)
{
printf("nnData is ERROR free, hence ACCEPTED... ");
}
else
{
printf("nnData is NOT ERROR free, hence NOT ACCEPTED...");
}
}

int sum1(int x,int y,int z)
{
if(x==0 && y==0 && z==0 && carry==0)
{
carry=0;
return(0);
}
else if(x==1 && y==0 && z==0 && carry==0)
{
carry=0;
return(1);

29

}
else if(x==0 && y==1 && z==0 && carry==0)
{
carry=0;
return(1);
}
else if(x==1 && y==1 && z==0 && carry==0)
{
carry=1;
return(0);
}
else if(x==0 && y==0 && z==1 && carry==0)
{
carry=0;
return(1);
}
else if(x==1 && y==0 && z==1 && carry==0)
{
carry=1;
return(0);
}
else if(x==0 && y==1 && z==1 && carry==0)
{
carry=1;
return(0);
}
else if(x==1 && y==1 && z==1 && c==0)
{
carry=1;
return(1);
}
else if(x==0 && y==0 && z==0 && carry==1)
{
carry=0;
return(1);
}
else if(x==1 && y==0 && z==0 && carry==1)
{
carry=1;
return(0);
}
else if(x==0 && y==1 && z==0 && carry==1)
{
carry=1;
return(0);
}

30

else if(x==1 && y==1 && z==0 && carry==1)
{
carry=1;
return(1);
}
else if(x==0 && y==0 && z==1 && carry==1)
{
carry=1;
return(0);
}
else if(x==1 && y==0 && z==1 && carry==1)
{
carry=1;
return(1);
}
else if(x==0 && y==1 && z==1 && carry==1)
{
carry=1;
return(1);
}
else
return(1);
}

Output:-

****************************** CHECKSUM *****************************

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


31

1. Sender's Site

2. Receiver's Site

3. Exit

-----------------------------------------------------------------------------------------------------------
-
Sender's Site
-----------------------------------------------------------------------------------------------------------
-

Enter the total number of bits : 5

Enter 5 bits of Data 1 :

Enter bit 1: 1

Enter bit 2: 0

Enter bit 3: 1

Enter bit 4: 1

Enter bit 5: 0

-----------------------------------------------------------------------------------------------------------
-


Enter bit 1: 0

Enter bit 2: 1

Enter bit 3: 0
Enter bit 4: 0

Enter bit 5: 1

-----------------------------------------------------------------------------------------------------------
-

32

Output
-----------------------------------------------------------------------------------------------------------
-

Data 1: 10110

Data 2: 01001

Result : 11111

1's Compliment of Result :00000

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


-----------------------------------------------------------------------------------------------------------
-
Receiver's Site
-----------------------------------------------------------------------------------------------------------
-

Enter the total number of bits : 5


Enter bit 1: 0

Enter bit 2: 0

Enter bit 3: 0

Enter bit 4: 0

33

Enter bit 5: 1
-----------------------------------------------------------------------------------------------------------
-


Enter bit 1: 1

Enter bit 2: 2

Invalid Bit......Enter another value(only 1's and 0's)!!!!!

Enter bit 2: 1

Enter bit 3: 1

Enter bit 4: 1

Enter bit 5: 0

-----------------------------------------------------------------------------------------------------------
-

Enter 5 bits of Checksum :

Enter bit 1: 0

Enter bit 2: 0

Enter bit 3: 0

Enter bit 4: 0

Enter bit 5: 0

-----------------------------------------------------------------------------------------------------------
-
Output
-----------------------------------------------------------------------------------------------------------
-

Data 1: 00001

34

Data 2: 11110

Checksum: 00000

Result : 11111

1's Compliment of Result :00000

Data is ERROR free, hence ACCEPTED...

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


35

-5- HAMMING CODE

#include<stdio.h>
#include<conio.h>
#include<math.h>
void sender();
void receiver();
int a,m,r,i,count=0,n,count1=0;
void main()
{
int ans;
clrscr();
printf("nn*********************** HAMMING CODE
***********************nn");
while(1)
{
printf("n--------------------------------------------------------------------------n
");
printf("ttttnMAIN MENU");
printf("n--------------------------------------------------------------------------n
n");
scanf("%d",&ans);
switch(ans)
{
case 1:
printf("n-----------------------------------------------------------
--------------n");
printf("n-----------------------------------------------------------
--------------n");
sender();
break;
case 2:
printf("n-----------------------------------------------------------
--------------n");

36

printf("n-----------------------------------------------------------
--------------n");
receiver();
break;
case 3:
exit(1);
default:
}
}
}

void sender()
{
int data[20];
printf("Enter the number of data bits (MAX 11) : ");
scanf("%d",&m);
for(i=0;i<20;i++)
data[i]=0;
while(pow(2,r)-r<m+1)
r++;
printf("nThe Parity Bits are : %d n",r);
for(i=1;i<9;i++)
{
if(i==1||i==2||i==4||i==8)
{
data[i]=4;
}
}
printf("nEnter %d data bits : ",m);
for(i=1;i<=m+r;i++)
{
if(i==3||i==5||i==6||i==7||i==9||i==10||i==11||i==12||i==13||i==14||i==15||
i==16)
{
if (data[i]!=0&&data[i]!=1)
{
printf("Invalid Entry!!! Enter only 0's and 1's");
i--;
}
}
}
printf("nData Is : ");
for(i=1;i<=m+r;i++)
{

37

printf("%d ",data[i]);
}
for(i=1;i<=m+r;i++)
{
if(data[i]==4)
{
a=i;
}
if(a==1)
{
count=data[3]+data[5]+data[7]+data[9]+data[11];
if(count%2==0)
data[a]=0;
else
data[a]=1;
}
if(a==2)
{
count=data[3]+data[6]+data[7]+data[10]+data[11];
if(count%2==0)
data[a]=0;
else
data[a]=1;
}
if(a==4)
{
count=data[5]+data[6]+data[7];
if(count%2==0)
data[a]=0;
else
data[a]=1;
}
if(a==8)
{
count=data[9]+data[10]+data[11];
if(count%2==0)
data[a]=0;
else
data[a]=1;
}
}
printf("nn-----------------------------------------------------------------------------n");
printf("tttOutput");
printf("n--------------------------------------------------------------------------------n");
printf("nnNew Data To Be Sent Is : ");
for(i=1;i<=m+r;i++)

38

}

void receiver()
{
int data[20],temp;
printf("nEnter the number of data bits : ");
scanf("%d",&m);
for(i=0;i<20;i++)
data[i]=0;
printf("nEnter %d data bits : ",m);
for(i=1;i<=m;i++)
{
if (data[i]!=0&&data[i]!=1)
{
printf("Invalid Entry!!! Enter only 0's and 1's");
i--;
}
}
for(i=1;i<=m;i++)
{
if(i==1)
{
count=data[1]+data[3]+data[5]+data[7]+data[9]+data[11];
if(count%2==0)
{
data[i]=data[i];
}
else
{
count1=count1+i;
}
}
if(i==2)
{
count=data[2]+data[3]+data[6]+data[7]+data[10]+data[11];
if(count%2==0)
{
data[i]=data[i];
}
else
{

39

count1=count1+i;
}
}
if(i==4)
{
count=data[4]+data[5]+data[6]+data[7];
if(count%2==0)
{
data[i]=data[i];
}
else
{
count1=count1+i;
}
}
if(i==8)
{
count=data[8]+data[9]+data[10]+data[11];
if(count%2==0)
{
data[i]=data[i];
}
else
{
count1=count1+i;
}
}
}
printf("nn-----------------------------------------------------------------------------n");
printf("ttOutputn");
printf("n--------------------------------------------------------------------------------n");
if(count1>0)
{
if(count1>m)
{
printf("nError Is At Position %d",count1);
printf("nnOOPS!!! Position is not availablen");
}
else
{
printf("nError Is At Position %d",count1);
if(data[count1]==0)
data[count1]=1;
else
data[count1]=0;
printf("nCorrect Code Word : ");

40

for(i=1;i<=m;i++)
{
}
}
}
else
{
printf("nReceived Data Is ERROR FREE... n");
printf("nCorrect Code Word : ");
for(i=1;i<=m;i++)
{
}
}
}

41

Output:-

***************************** HAMMING CODE *************************

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


-----------------------------------------------------------------------------------------------------------
-
Sender's Site
-----------------------------------------------------------------------------------------------------------
-

Enter the number of data bits (MAX 11) : 7

The Parity Bits are : 4

Enter 7 data bits : 1 0 0 1 0 1 1

Data Is : 4 4 1 4 0 0 1 4 0 1 1

-----------------------------------------------------------------------------------------------------------
-
Output
-----------------------------------------------------------------------------------------------------------
-

42

New Data To Be Sent Is : 1 0 1 1 0 0 1 0 0 1 1

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


-----------------------------------------------------------------------------------------------------------
-
Receiver's Site
-----------------------------------------------------------------------------------------------------------
-

Enter the number of data bits : 11

Enter 11 data bits : 1 0 1 1 0 0 1 0 1 1 1

-----------------------------------------------------------------------------------------------------------
-
Output
-----------------------------------------------------------------------------------------------------------
-

Error Is At Position 9

Correct Code Word : 1 0 1 1 0 0 1 0 0 1 1

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


43

1. Sender's Site

2. Receiver's Site

3. Exit


-6- BIT STUFFING

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
void sender();
void receiver();
int data[20],i,j,n,count=0;
void main()
{
int choice;
clrscr();
printf("********************************** BIT STUFFING
********************************");
while(1)
{
printf("nn--------------------------------------------------------------------------
n");
printf("n--------------------------------------------------------------------------n
n");

44

switch(choice)
{
case 1:
printf("n-----------------------------------------------------------
--------------n");
printf("n-----------------------------------------------------------
--------------n");
sender();
break;
case 2:
printf("n-----------------------------------------------------------
--------------n");
printf("n-----------------------------------------------------------
--------------n");
receiver();
break;
case 3:
exit(1);
default:
printf("nInvalid Choice!!!");
}
}
}

void sender()
{
printf("nEnter the length of your code : ");
scanf("%d",&n);
for(i=0;i<n;i++)
{
printf("nEnter %d bit : ",i+1);
}
printf("nnThe Original Data entered : ");
for(i=0;i<n;i++)
{
}
i=0;
while(i<n)
{
if(data[i]==1)
{
i++;

45

count++;
if(count==5)
{
for(j=n+1;j>i;j--)
{
data[j]=data[j-1];
}
data[i]=0;
}
}
else
{
i++;
count=0;
}
}
printf("nn--------------------------------------------------------------------------n");
printf("ttt Outputn");
printf("-------------------------------------------------------------------------------n");
printf("nnData After Stuffing : ");
for(i=0;i<n+1;i++)
{
}
}

void receiver()
{
printf("nEnter the length of your code : ");
scanf("%d",&n);
for(i=0;i<n;i++)
{
printf("nEnter %d bit : ",i+1);
}
printf("nnThe Original Data entered : ");
for(i=0;i<n;i++)
{
}
i=0;
while(i<n)
{
if(data[i]==1)
{
i++;

46

count++;
if(count==5)
{
for(j=i;j<n+1;j++)
{
data[j]=data[j+1];

}
n--;
}
}
else
{
i++;
count=0;
}
}
printf("nn--------------------------------------------------------------------------------");
printf("nttt Output");
printf("n--------------------------------------------------------------------------------n");
printf("nData After De-Stuff : ");
for(i=0;i<n;i++)
{
}
}

47

Output:-

****************************** BIT STUFFING **************************

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


-----------------------------------------------------------------------------------------------------------
-
Sender's Site
-----------------------------------------------------------------------------------------------------------
-

48

Enter the length of your code : 11

Enter 1 bit : 0

Enter 2 bit : 1

Enter 3 bit : 1

Enter 4 bit : 1

Enter 5 bit : 1

Enter 6 bit : 1

Enter 7 bit : 1

Enter 8 bit : 0

Enter 9 bit : 1

Enter 10 bit : 1

Enter 11 bit : 0

The Original Data entered : 0 1 1 1 1 1 1 0 1 1 0

-----------------------------------------------------------------------------------------------------------
-
Output
-----------------------------------------------------------------------------------------------------------
-

Data After Stuffing : 0 1 1 1 1 1 0 1 0 1 1 0

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

49

3. Exit


-----------------------------------------------------------------------------------------------------------
-
Receiver's Site
-----------------------------------------------------------------------------------------------------------
-

Enter the length of your code : 11

Enter 1 bit : 0

Enter 2 bit : 1

Enter 3 bit : 1

Enter 4 bit : 1

Enter 5 bit : 1

Enter 6 bit : 1

Enter 7 bit : 0

Enter 8 bit : 0

Enter 9 bit : 1

Enter 10 bit : 0

Enter 11 bit : 1

The Original Data entered : 0 1 1 1 1 1 0 0 1 0 1

-----------------------------------------------------------------------------------------------------------
-
Output
-----------------------------------------------------------------------------------------------------------
-

Data After De-Stuff : 0 1 1 1 1 1 0 1 0 1

-----------------------------------------------------------------------------------------------------------
-

50

MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


-7- WALSH MATRIX

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
void stn1();
void stn2();
void stn4();
int n,i,j;
void main()
{

51

clrscr();
printf("n***************** CHIPPING SEQUENCE USING WALSH
MATRIX *********************nn");
while(1)
{
printf("n--------------------------------------------------------------------------n
");
printf("n--------------------------------------------------------------------------n
n");
printf("Choice No. Station No.nn");
printf(" 1. Station 1nn 2. Station 2nn 3. Station 4nn
4. ExitnnEnter Your Choice : ");
scanf("%d",&n);
switch(n)
{
case 1:
printf("n-----------------------------------------------------------
--------------n");
printf("ttt Station 1");
printf("n-----------------------------------------------------------
--------------n");
stn1();
break;
case 2:
printf("n-----------------------------------------------------------
--------------n");
printf("n-----------------------------------------------------------
--------------n");
stn2();
break;
case 3:
printf("n-----------------------------------------------------------
--------------n");
printf("n-----------------------------------------------------------
--------------n");
stn4();
break;
case 4:
exit(1);
default:
printf("nnInvalid Entry!!!");
}
}

52

}

void stn1()
{
int w1;
printf("nYour Code For Station 1 : 1n");
}

void stn2()
{
int w2[2][2];
for(i=0;i<2;i++)
{
for(j=0;j<2;j++)
{
if ((i==1) && (j==1))
{
w2[i][j]=-1;
}
else
{
w2[i][j]=1;
}
}
}
printf("nYour Code For Station 2 : nn");
for(i=0;i<2;i++)
{
for(j=0;j<2;j++)
{
printf("%d ",w2[i][j]);
}
printf("n");
}
}

void stn4()
{
int w4[4][4];
for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
{
if(i==0)
{
w4[i][j]=1;

53

}
else if(j==0)
{
w4[i][j]=1;
}
else if((i==1)&&(j==1))
{
w4[i][j]=-1;
}
else if((i==1)&&(j==3))
{
w4[i][j]=-1;
}
else if((i==2)&&(j==2))
{
w4[i][j]=-1;
}
else if((i==2)&&(j==3))
{
w4[i][j]=-1;
}
else if((i==3)&&(j==1))
{
w4[i][j]=-1;
}
else if((i==3)&&(j==2))
{
w4[i][j]=-1;
}
else
{
w4[i][j]=1;
}
}
}
printf("nYour Code For Station 4 : nn");
for(i=0;i<4;i++)
{
for(j=0;j<4;j++)
{
printf("%dt",w4[i][j]);
}
printf("n");
}
}

54

Output:-

************** CHIPPING SEQUENCE USING WALSH MATRIX ***********

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-

Choice No. Station No.

1. Station 1

55

2. Station 2

3. Station 4

4. Exit


-----------------------------------------------------------------------------------------------------------
-
Station 1
-----------------------------------------------------------------------------------------------------------
-

Your Code For Station 1 : 1

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Station 1

2. Station 2

3. Station 4

4. Exit


Invalid Entry!!!

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


56

1. Station 1

2. Station 2

3. Station 4

4. Exit


-----------------------------------------------------------------------------------------------------------
-
Station 2
-----------------------------------------------------------------------------------------------------------
-

Your Code For Station 2 :

1 1
1 -1

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Station 1

2. Station 2

3. Station 4

4. Exit


57

-----------------------------------------------------------------------------------------------------------
-
Station 4
-----------------------------------------------------------------------------------------------------------
-

Your Code For Station 4 :

1 1 1 1
1 -1 1 -1
1 1 -1 -1
1 -1 -1 1

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Station 1

2. Station 2

3. Station 4

4. Exit


58

-8- BIT COMPRESSION

#include<stdio.h>
#include<conio.h>
void main()
{
int i,j,a[20],cnt1,cnt2,n;
clrscr();
printf("n************************** BIT COMPRESSION
************************************n");
printf("nnEnter the length of Data ( <= 20 ) : ");
scanf("%d",&n);
printf("nnEnter %d Bits : n",n);
for(i=1;i<=n;i++)
{
printf("nnEnter Bit %d:",i);
scanf("%d",&a[i]);
}
printf("nnOriginal Data : ");
for(i=1;i<=n;i++)
{
printf("%d ",a[i]);
}
cnt1=0;
cnt2=0;
printf("nn-----------------------------------------------------------------------------n");
printf("ttt Output");
printf("n-------------------------------------------------------------------------------n");
printf("nThe Data Contains : n");
for(i=1;i<=n;i++)
{
if(a[i]==1)
{
if(cnt2!=0)
{
printf("nn 0's : %d",cnt2);
cnt2=0;
}
cnt1++;

}

59

if(a[i]==0)
{
if(cnt1!=0)
{
cnt1=0;
}
cnt2++;
}
}
if(cnt1==0)
if(cnt2==0)
getch();
}

60

Output:-

************************** BIT COMPRESSION **************************

Enter the length of Data : 11

Enter 11 Bits :

Enter Bit 1 : 1

Enter Bit 2 : 1

Enter Bit 3 : 0

Enter Bit 4 : 0

Enter Bit 5 : 0

Enter Bit 6 : 0

Enter Bit 7 : 1

Enter Bit 8 : 1

Enter Bit 9 : 0

Enter Bit 10 : 1

Enter Bit 11 :1

Original Data : 1 1 0 0 0 0 1 1 0 1 1

-----------------------------------------------------------------------------------------------------------
-
Output
-----------------------------------------------------------------------------------------------------------
-
The Data Contains :

1's : 2

0's : 4

61

1's : 2

0's : 1

1's : 2
-9- MONOALPHABETIC ENCRYPTION

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<ctype.h>

void sender();
void receiver();
void main()
{
int choice;
clrscr();
printf("n************************** MONOALPHABETIC
ENCRYPTION ***********************n");
while(1)
{
printf("nn--------------------------------------------------------------------------
n");
printf("n--------------------------------------------------------------------------n
n");
switch(choice)
{
case 1:
printf("n-----------------------------------------------------------
--------------n");
printf("n-----------------------------------------------------------
--------------n");
sender();
break;
case 2:
printf("n-----------------------------------------------------------
--------------n");

62


printf("n-----------------------------------------------------------
--------------n");
receiver();
break;

case 3:
exit(1);
default:
printf("nnInvalid Entry");
}
}
}

void sender()
{
int i,n;
char *ptr,*str,*str1;
printf("nEnter the Plain Text : ");
scanf("%s",str);
printf("nEnter the Charter difference : ");
scanf("%d",&n);
printf("n-----------------------------------------------------------------------nn");
printf("nPlain Text : ");
printf("%s",str);
printf("nnCipher Text After Encryption : ");
for(i=0;str[i]!='0';i++)
{
if((str[i]>=65 && str[i]<=90-n) || (str[i]>=97 && str[i]<=122-n))
{
ptr[i]=str[i]+n;
}
else if((str[i]>90-n && str[i]<=90)||(str[i]>122-n && str[i]<=122))
{
ptr[i]=str[i]-26+n;
}
else
{
ptr[i]=str[i];
}
}
ptr[i]='0';
printf("%s",ptr);
}

63

void receiver()
{
int i,n;
char *ptr,*str,*str1;
printf("nEnter the Cipher text : ");
scanf("%s",ptr);
printf("nEnter the Charter difference : ");
scanf("%d",&n);
printf("n-----------------------------------------------------------------------nn");
printf("nCipher Text : ");
printf("%s",ptr);
printf("nnPlain text After Decryption : ");
for(i=0;ptr[i]!='0';i++)
{
if((ptr[i]>=65+n && ptr[i]<=90) || (ptr[i]>=97+n && ptr[i]<=122))
{
str1[i]=ptr[i]-n;
}
else if((ptr[i]>=65 && ptr[i]<=65+n)||(ptr[i]>=97 && ptr[i]<=97+n))
{
str1[i]=ptr[i]+26-n;
}
else
{
str1[i]=ptr[i];
}
}
str1[i]='0';
printf("%s",str1);
}

64

Output:-

********************* MONOALPHABETIC ENCRYPTION ****************

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


-----------------------------------------------------------------------------------------------------------
-
Sender's Site
-----------------------------------------------------------------------------------------------------------
-

Enter the Plain Text : TARANNUM

Enter the Charter difference : 5

-----------------------------------------------------------------------------------------------------------
-

Plain Text : TARANNUM

Cipher Text After Encryption : YFWFSSZR

65

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

3. Exit


-----------------------------------------------------------------------------------------------------------
-
Receiver's Site
-----------------------------------------------------------------------------------------------------------
-

Enter the Cipher text : yfwfsszr

Enter the Charter difference : 5

-----------------------------------------------------------------------------------------------------------
-

Cipher Text : yfwfsszr

Plain text After Decryption : tarannum

-----------------------------------------------------------------------------------------------------------
-
MAIN MENU
-----------------------------------------------------------------------------------------------------------
-


1. Sender's Site

2. Receiver's Site

66

3. Exit


-10- POLYALPHABETIC ENCRYPTION

#include <stdio.h>
#include <string.h>

void main()
{
unsigned int i,j=1,k;
char input[257],key[33],l[257];
clrscr();
k=65;
printf("n************************** POLYALPHABETIC
ENCRYPTION ***************************n");
printf("ntttt VIGENERE TABLE nn");
printf("------------------------------------------------------------------------------nn");
while (j <= 26)
{
for (i=j; i<j+26; i++)
{
if (k >90)
k = k - 26;
printf("%c ",k );
k++;
}
printf("n");

67

j++;
k++;
}
printf("n----------------------------------------------------------------------------nn");
printf("nEnter Plain Text : ");
gets(input);
printf("nEnter Encryption Key : ");
gets(key);
printf("n----------------------------------------------------------------------------n");
printf("nKEY : t ");
for(i=0,j=0;i<strlen(input);i++,j++)
{

if(j>=strlen(key))
{
j=0;
}
l[i]=key[j];
}
for(i=0;i<strlen(input);i++)
{
printf("%c",l[i]);
}
printf("nnPlain Text : ");
printf("%s",input);
printf("nnCipher Text : ");
for(i=0,j=0;i<strlen(input);i++,j++)
{
if(j>=strlen(key))
{
j=0;
}
printf("%c",65+(((toupper(input[i])-65)+(toupper(key[j])-65))
%26));
}
getch();
}

68

Output:-

********************* POLYALPHABETIC ENCRYPTION *****************

VIGENERE TABLE

-----------------------------------------------------------------------------------------------------------
-

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
B C D E F G H I J K L M N O P Q R S T U V W X Y Z A
C D E F G H I J K L M N O P Q R S T U V W X Y Z A B
D E F G H I J K L M N O P Q R S T U V W X Y Z A B C
E F G H I J K L M N O P Q R S T U V W X Y Z A B C D
F G H I J K L M N O P Q R S T U V W X Y Z A B C D E
G H I J K L M N O P Q R S T U V W X Y Z A B C D E F
H I J K L M N O P Q R S T U V W X Y Z A B C D E F G
I J K L M N O P Q R S T U V W X Y Z A B C D E F G H
J K L M N O P Q R S T U V W X Y Z A B C D E F G H I
K L M N O P Q R S T U V W X Y Z A B C D E F G H I J
L M N O P Q R S T U V W X Y Z A B C D E F G H I J K
M N O P Q R S T U V W X Y Z A B C D E F G H I J K L
N O P Q R S T U V W X Y Z A B C D E F G H I J K L M
O P Q R S T U V W X Y Z A B C D E F G H I J K L M N
P Q R S T U V W X Y Z A B C D E F G H I J K L M N O

69

Q R S T U V W X Y Z A B C D E F G H I J K L M N O P
R S T U V W X Y Z A B C D E F G H I J K L M N O P Q
S T U V W X Y Z A B C D E F G H I J K L M N O P Q R
T U V W X Y Z A B C D E F G H I J K L M N O P Q R S
U V W X Y Z A B C D E F G H I J K L M N O P Q R S T
V W X Y Z A B C D E F G H I J K L M N O P Q R S T U
W X Y Z A B C D E F G H I J K L M N O P Q R S T U V
X Y Z A B C D E F G H I J K L M N O P Q R S T U V W
Y Z A B C D E F G H I J K L M N O P Q R S T U V W X
Z A B C D E F G H I J K L M N O P Q R S T U V W X Y

-----------------------------------------------------------------------------------------------------------
-

Enter Plain Text : HIWORLD

Enter Encryption Key : ME

-----------------------------------------------------------------------------------------------------------
-

KEY : MEMEMEM

Plain Text : HIWORLD

Cipher Text : TMISDPP

70

-11- RSA ALGORITHM

#include<stdio.h>
#include<conio.h>
#include<math.h>

int phi,m,n,e,d,c,flg;
void check()
{
int i;
for(i=3;e%i==0 && phi%i==0;i+2)
{
flg = 1;
return;
}
flg = 0;
}

void encrypt()
{
int i;
c = 1;

71

for(i=0;i<e;i++)
c=c*m%n;
c=c%n;
printf("nEncrypted Plain Text : %d",c);
printf("nn----------------------------------------------------------------------n");
}

void decrypt()
{
int i;
m = 1;
for(i=0;i< d;i++)
m=m*c%n;
m = m%n;
printf("nDecrypted Cipher Text : %d",m);
}

void main()
{
int p,q,s;
clrscr();
printf("n************************* RSA ALGORITHM
*****************************nn");
printf("nEnter Two Relative Prime Numbers : ");
scanf("%d%d",&p,&q);
n = p*q;
phi=(p-1)*(q-1);
printf("nF(n)t = %d",phi);
do
{
printf("nnEnter value for e : ");
scanf("%d",&e);
check();
}while(flg==1);
d = 1;
do
{
s = (d*e)%phi;
d++;
}while(s!=1);
d = d-1;
printf("n-----------------------------------------------------------------------------nn");
printf("nPublic Keyt: {%d,%d}",e,n);
printf("nnPrivate Keyt: {%d,%d}",d,phi);
printf("nn---------------------------------------------------------------------------nn");
printf("nEnter The Plain Text : ");

72

scanf("%d",&m);
encrypt();
printf("nnEnter the Cipher text : ");
scanf("%d",&c);
decrypt();
getch();
}

Output:-

**************************** RSA ALGORITHM *************************

Enter Two Relative Prime Numbers : 7 11

F(n) = 60

Enter value for e : 13

-----------------------------------------------------------------------------------------------------------
-

Public Key : {13,77}

Private Key : {37,60}

-----------------------------------------------------------------------------------------------------------
-

Enter The Plain Text : 7

Encrypted Plain Text : 35

73

-----------------------------------------------------------------------------------------------------------
-

Enter the Cipher text : 35

Decrypted Cipher Text : 7

-12-DIJKSTRA’S SHORTEST PATH

#include<stdio.h>
#include<conio.h>

#define MAX 10
#define TEMP 0
#define PERM 1
#define infinity 9999

struct node
{
int predecessor;
int dist;
int status;
};

int adj[MAX][MAX];
int n;
void main()

74

{
int i,j;
int source,dest;
int path[MAX];
int shortdist,count;
clrscr();
printf("************************ DIJKSTRA'S SHORTEST PATH
**********************");
create_graph();
printf("The adjacency matrix is :n");
display();
while(1)
{
printf("nEnter source node(0 to quit) : ");
scanf("%d",&source);
printf("nEnter destination node(0 to quit) : ");
scanf("%d",&dest);

if(source==0 || dest==0)
exit(1);

count = findpath(source,dest,path,&shortdist);
if(shortdist!=0)
{
printf("nShortest distance is : %dn", shortdist);
printf("nShortest Path is : ");
for(i=count;i>1;i--)
printf("%d->",path[i]);
printf("%d",path[i]);
printf("n");
}
else
printf("nThere is no path from source to destination
noden");
}
getch();
}

create_graph()
{
int i,max_edges,origin,destin,wt;

printf("Enter number of vertices : ");
scanf("%d",&n);
max_edges=n*(n-1);

75

for(i=1;i<=max_edges;i++)
{
printf("nEnter edge %d(0 0 to quit) : ",i);
scanf("%d %d",&origin,&destin);
if((origin==0) && (destin==0))
break;
printf("nEnter weight for this edge : ");
scanf("%d",&wt);
if( origin > n || destin > n || origin<=0 || destin<=0)
{
printf("nInvalid edge!n");
i--;
}
else
adj[origin][destin]=wt;
}
}

display()
{
int i,j;
for(i=1;i<=n;i++)
{
for(j=1;j<=n;j++)
printf("%3d",adj[i][j]);
printf("n");
}

}

int findpath(int s,int d,int path[MAX],int *sdist)
{
struct node state[MAX];
int i,min,count=0,current,newdist,u,v;
*sdist=0;
for(i=1;i<=n;i++)
{
state[i].predecessor=0;
state[i].dist = infinity;
state[i].status = TEMP;
}
state[s].predecessor=0;
state[s].dist = 0;
state[s].status = PERM;
current=s;
while(current!=d)

76

{
for(i=1;i<=n;i++)
{
if ( adj[current][i] > 0 && state[i].status == TEMP )
{
newdist=state[current].dist + adj[current][i];
if( newdist < state[i].dist )
{
state[i].predecessor = current;
state[i].dist = newdist;
}
}
}
min=infinity;
current=0;
for(i=1;i<=n;i++)
{
if(state[i].status == TEMP && state[i].dist < min)
{
min = state[i].dist;
current=i;
}
}

if(current==0)
return 0;
state[current].status=PERM;
}
while( current!=0 )
{
count++;
path[count]=current;
current=state[current].predecessor;
}
for(i=count;i>1;i--)
{
u=path[i];
v=path[i-1];
*sdist+= adj[u][v];
}
return (count);
}

77

Output:-

********************** DIJKSTRA'S SHORTEST PATH *******************

Enter number of vertices : 6

Enter edge 1(0 0 to quit) : 1 2

Enter weight for this edge : 6






78











The adjacency matrix is :
0 6 0 0 0 0
0 0 0 0 3 2
0 0 0 2 0 3
0 0 0 0 0 1
0 0 0 4 0 0
0 0 0 0 3 0

Enter source node(0 to quit) : 1

Enter destination node(0 to quit) : 6

Shortest distance is : 8

Shortest Path is : 1->2->6


Enter destination node(0 to quit) :4

79

Shortest distance is : 7

Shortest Path is : 2->5->4


Enter destination node(0 to quit) : 0

-13-PRIM’S ALGORITHM

#include<stdio.h>
#include<conio.h>

#define MAX 10
#define TEMP 0
#define PERM 1
#define FALSE 0
#define TRUE 1
#define infinity 9999

struct node
{
int predecessor;
int dist;
int status;
};

80

struct edge
{
int u;
int v;
};

int adj[MAX][MAX];
int n;

main()
{
int i,j;
int path[MAX];
int wt_tree,count;
struct edge tree[MAX];
clrscr();
printf("********* MINIMUM SPANNING TREE FROM PRIM'S
ALGORITHM ********n");
create_graph();
printf("nAdjacency matrix is : nn");
display();

count = maketree(tree,&wt_tree);

printf("nWeight of spanning tree is : %dn", wt_tree);
printf("nEdges to be included in spanning tree are : nn");
for(i=1;i<=count;i++)
{
printf("%d->",tree[i].u);
printf("%dn",tree[i].v);
}
getch();
}

create_graph()
{
int i,max_edges,origin,destin,wt;

printf("nEnter number of vertices : ");
scanf("%d",&n);
max_edges=n*(n-1)/2;

for(i=1;i<=max_edges;i++)
{
printf("nEnter edge %d(0 0 to quit) : ",i);

81

scanf("%d %d",&origin,&destin);
if((origin==0) && (destin==0))
break;
printf("nEnter weight for this edge : ");
scanf("%d",&wt);
if( origin > n || destin > n || origin<=0 || destin<=0)
{
printf("nInvalid edge!n");
i--;
}
else
{
adj[origin][destin]=wt;
adj[destin][origin]=wt;
}
}
if(i<n-1)
{
printf("nSpanning tree is not possiblen");
exit(1);
}
}

display()
{
int i,j;
for(i=1;i<=n;i++)
{
for(j=1;j<=n;j++)
printf("%3d",adj[i][j]);
printf("n");
}
}

int maketree(struct edge tree[MAX],int *weight)
{
struct node state[MAX];
int i,k,min,count,current,newdist;
int m;
int u1,v1;
*weight=0;
for(i=1;i<=n;i++)
{
state[i].predecessor=0;
state[i].dist = infinity;
state[i].status = TEMP;

82

}
state[1].predecessor=0;
state[1].dist = 0;
state[1].status = PERM;

current=1;
count=0;
while( all_perm(state) != TRUE )
{
for(i=1;i<=n;i++)
{
if ( adj[current][i] > 0 && state[i].status == TEMP )
{
if( adj[current][i] < state[i].dist )
{
state[i].predecessor = current;
state[i].dist = adj[current][i];
}
}
}

min=infinity;
for(i=1;i<=n;i++)
{
if(state[i].status == TEMP && state[i].dist < min)
{
min = state[i].dist;
current=i;
}
}

state[current].status=PERM;
u1=state[current].predecessor;
v1=current;
count++;
tree[count].u=u1;
tree[count].v=v1;
*weight=*weight+adj[u1][v1];
}
return (count);
}
int all_perm(struct node state[MAX] )
{
int i;
for(i=1;i<=n;i++)
if( state[i].status == TEMP )

83

return FALSE;
return TRUE;
}

Output:-

******** MINIMUM SPANNING TREE FROM PRIM'S ALGORITHM ********

Enter number of vertices : 7








84



















Adjacency matrix is :

0 3 10 2 4 0 0
3 0 0 0 7 0 0
10 0 0 12 0 15 0
2 0 12 0 6 4 0
4 7 0 6 0 5 2
0 0 15 4 5 0 3
0 0 0 0 2 3 0

85

Weight of spanning tree is : 24

Edges to be included in spanning tree are :

1->4
1->2
1->5
5->7
7->6
1->3

86

Dcn code and output

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