Implementation of Hamming Code

C program

#include<stdio.h>
#include<conio.h>
void main() {
 int data[7],rec[7],i,c1,c2,c3,c;
 printf("this works for message of 4bits in size \nenter message bit one by one:  ");
 scanf("%d%d%d%d",&data[0],&data[1],&data[2],&data[4]);
 data[6]=data[0]^data[2]^data[4];
 data[5]=data[0]^data[1]^data[4];
 data[3]=data[0]^data[1]^data[2];
 printf("\nthe encoded bits are given below: \n");
 for (i=0;i<7;i++) {
  printf("%d ",data[i]);
 }
 printf("\nenter the received data bits one by one: ");
 for (i=0;i<7;i++) {
  scanf("%d",&rec[i]);
 }
 c1=rec[6]^rec[4]^rec[2]^rec[0];
 c2=rec[5]^rec[4]^rec[1]^rec[0];
 c3=rec[3]^rec[2]^rec[1]^rec[0];
 c=c3*4+c2*2+c1 ;
 if(c==0) {
  printf("\ncongratulations there is no error: ");
 } else {
  printf("\nerron on the postion: %d\nthe correct message is \n",c);
  if(rec[7-c]==0)
      rec[7-c]=1; else
      rec[7-c]=0;
  for (i=0;i<7;i++) {
   printf("%d ",rec[i]);
  }
 }
 getch();
}

Output