CRC Cyclic Redundancy Check

This program to implement Cyclic Redundancy Check (CRC). This is a part of Mumbai University MCA Colleges Data Communication and Networking MCA Sem 4

#include<stdio.h>

#include<conio.h>

int rem(int,int);

void main()

{

  int i,j,k,dl,dil;

  int data[10],div[5],newdata[15],crc[5],datacrc[15],revdata[15],remd[5];

  clrscr();

  printf("\n Enter the data length= ");

  scanf("%d",&dl);

  printf("\n Enter the divisor  length= ");

  scanf("%d",&dil);

  printf("\n Enter the data : ");

  for(i=0;i<dl;i++)

   scanf("%d",&data[i]);

  printf("\n Enter the divisor : ");

  for(i=0;i<dil;i++)

   scanf("%d",&div[i]);

  printf("\n The new data is : ");

  for(i=0;i<(dl+dil-1);i++)

  {

    if(i<dl)

     newdata[i]=data[i];

    else

     newdata[i]=0;

    printf("%d",newdata[i]);

  }

 for(j=0;j<=dl;j++)

 {

            for(i=0;i<dil;i++)

            {

             crc[i]=newdata[i+j];

             if(crc[0]==1)

              newdata[i+j]=rem(newdata[i+j],div[i]);

             else

              newdata[i+j]=rem(newdata[i+j],0);

            }

 printf("\n The Crc is : ");

 for(i=0;i<dil-1;i++)

  printf("%d",crc[i]);

 }

 printf("\n The data to be send is : ");

 for(i=0;i<(dl+dil-1);i++)

 {

  if(i<dl)

   datacrc[i]=data[i];

  else

   datacrc[i]=crc[i-dl];

  printf("%d",datacrc[i]);

 }

 printf("\n Enter the receiver side data : ");

 for(i=0;i<(dl+dil-1);i++)

  scanf("%d",&revdata[i]);

  for(j=0;j<=dl;j++)

 {

            for(i=0;i<dil;i++)

            {

             remd[i]=revdata[i+j];

             if(remd[0]==1)

              revdata[i+j]=rem(revdata[i+j],div[i]);

             else

              revdata[i+j]=rem(revdata[i+j],0);

            }

 printf("\n The reminder is : ");

 k=0;

 for(i=0;i<dil-1;i++)

  {

  printf("%d",remd[i]);

   if(remd[i]==0)

    k++;

  }

 }

 if(k==dil-1)

 printf("\n There is no error found.");

 else

 printf("\n There is error found.");

 getch();

}

int rem(int x, int y)

{

 if(x==y)

  return 0;

 else

  return 1;

}
Hope this Program is useful to you in some sense or other. Keep on following this blog for more Mumbai University MCA College Programs. Happy Programming and Studying.