hamming-working

#include<stdio.h>

void main() {

int data[10]; 
int dataatrec[10],c,c1,c2,c3,i; 
printf("Enter 4 bits of data one by one\n"); 
scanf("%d",&data[0]); 
scanf("%d",&data[1]); 
scanf("%d",&data[2]); 
scanf("%d",&data[4]); 

//Calculation of even parity 
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("\nEncoded data is\n"); 

for(i=0;i<7;i++) 
	printf("%d",data[i]); 

printf("\n\nEnter received data bits one by one\n"); 
for(i=0;i<7;i++) 
	scanf("%d",&dataatrec[i]); 
	
c1=dataatrec[6]^dataatrec[4]^dataatrec[2]^dataatrec[0]; 
c2=dataatrec[5]^dataatrec[4]^dataatrec[1]^dataatrec[0]; 
c3=dataatrec[3]^dataatrec[2]^dataatrec[1]^dataatrec[0]; 
c=c3*4+c2*2+c1 ; 
 
if(c==0) { 
	printf("\nNo error while transmission of data\n"); 
} 
else { 
	printf("\nError on position %d",c); 
 
	printf("\nData sent : "); 
	for(i=0;i<7;i++) 
		printf("%d",data[i]); 
	 
	printf("\nData received : "); 
	for(i=0;i<7;i++) 
		printf("%d",dataatrec[i]); 
	 
	printf("\nCorrect message is\n"); 
	 
	//if errorneous bit is 0 we complement it else vice versa 
	if(dataatrec[7-c]==0) 
		dataatrec[7-c]=1; 
	else 
		dataatrec[7-c]=0; 
	
	 
	for (i=0;i<7;i++) { 
		printf("%d",dataatrec[i]); 
    } 
} 
printf("\n");

}