Signed and Unsigned Binary addition

In this program, addition of the entered number was performed. The entered number may be signed or unsigned (positive or negative). After the addition, the output was displayed in the binary as well as in decimal.

Binary Addition

/**
//By: www.subirank.com (Suresh Ghatuwa)
//Binary Addition Using C Program
*/
#include<stdio.h>
#include<conio.h>
#include<math.h>
//Input the data function
int get()
{
int flag=0;
int a;
do
{

 printf("ENTER VALUE: ");
scanf("%d",&a);
if(a< 0)
{
a = a * -1;  // changing the negative value into positive
flag = 1;
}
if(a>16)      // limiting input value to 16
printf("\n\t!INVALID NUMBER.ENTER VALUE (-16 < A < 16)!");
}while(a>16);
if(flag)
a = a *-1;
return(a);
}

//binary addition
void add(int *a,int *b,int n)
{
  int i,j,carry=0;
  j=n-1;
  for(i=n-1;i>=0;i--)
  {
    if (a[i]==1 && b[i]==1 && carry ==1)
    {
      a[j] = 1;
      carry =1;
    }
    else if (a[i]==1 && b[i]==1 && carry ==0)
    {
        a[j]=0;
        carry=1;
    }
    else if (a[i]==0 && b[i]==1 && carry ==0)
    {
        a[j]=1;
        carry=0;
    }
    else if (a[i]==0 && b[i]==1 && carry ==1)
    {
      a[j]=0;
      carry=1;
    }
    else if (a[i]==1 && b[i]==0 && carry ==1)
    {
      a[j]=0;
      carry=1;
    }
    else if (a[i]==1 && b[i]==0 && carry ==0)
    {
      a[j]=1;
      carry=0;
    }
    else if (a[i]==0 && b[i]==0 && carry ==1)
    {
      a[j]=1;
      carry=0;
    }
    else if (a[i]==0 && b[i]==0 && carry ==0)
    {
      a[j]=0;
      carry=0;
    }

    j--;

  }
}

//Decinal to Binary Conversion
void binary(int x,int*arr,int n)
{
int i,p=x,c[8];
    c[0]=0;
    c[1]=0;
    c[2]=0;
    c[3]=0;
    c[4]=0;
    c[5]=0;
    c[6]=0;
    c[7]=1;
for(i=0;i<n;i++)
arr[i] = 0;
if(x < 0)
x = x * -1;
i = n-1;
do
{
arr[i]=x%2;
x = x/2;
i--;
}while(x!=0);
if(p< 0)
{
for(i=0;i< n;i++)
{
arr[i]=1-arr[i];
}
add(arr,c,n);
printf("\n");
}
printf("\n\nTHE BINARY EQUIVALENT OF %d IS : ",p);
for(i=0;i<n;i++)
printf("%d",arr[i]);
}

void main()
{
int i,j,a,b;
int s=0,z=0,Q[8],M[8],A[8]={0,0,0,0,0,0,0,1},n=0;
int p;
clrscr();
printf("\t\t\tBinary Addition Using C Program\n");
printf("--------------------------------------------------\n");
a = get();   // input the value a
b=get();     //input the value b

    n=8;

printf("---------------------------------------------------\n");
binary(a,M,n); //converting the input value a into its binary
binary(b,Q,n); //converting the input value b into its binary
printf("\n\n---------------------------------------------------\n");

add(M,Q,n);
printf("\n");
printf("The answer in Binary is: ");
for(i=0;i<n;i++)
{
    printf("%d",M[i]);
}
if((a<0 || b<0) && (b<a))
{
for(i=0;i<n;i++)
{
M[i] = 1-M[i];
}
add(M,A,n);
}
for(i=n-1;i>=0;i--)
{
s = s + (pow(2,z) * M[i]);
z = z+1;
}
if((a<0 || b<0)&&(b<a))
{
printf("\nThe answer in decimal is: -%d",s);
}
else
{
printf("\nThe answer in decimal is: %d",s);
}
getch();
}