C Program - Look Ahead Carry Adder

/* C Program For Implementation Of Look Ahead Carry Adder */

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

int get1(int a)
{
char ch='B';
if(a==1)
ch='A';
do
{
printf("\n\tENTER VALUE OF %c:",ch);
scanf("%d",&a);
if(a< =0)
printf("\n\t\t!INVALID NUMBER.ENTER VALUE (0< A)!");
}while(a< =0);
return(a);
}

int and(int a,int b)
{
int c;
if(a< b)
c=a;
else
c=b;
return (c);
}

int or(int a,int b)
{
int x;
if(a>b)
x=a;
else
x=b;
return x;
}

int exor(int a,int b)
{
int x;
if(a==b)
x=0;
else
x=1;
return x;
}


void add()
{
int i=7,A,B,a,b,cin,num;
int n1[8],n2[8],cg[8],cp[8],sum[8];
for(i=0;i< =7;i++)
{
n1[i]=0; // Num 1
n2[i]=0; // Num 2
cg[i]=0; // Gi
cp[i]=0; // Pi
sum[i]=0; // Sum
}
A = a = get1(1);
B = b = get1(0);
i=7;
do
{
n1[i]=a%2;
a=a/2;
n2[i]=b%2;
b=b/2;
i--;
}while((a!=0)||(b!=0));
i=0;
printf("\n\t\t Binary Form",A);
printf("\n\t A = %d : ",A);
for(i=0;i< =7;i++)
printf("%d ",n1[i]);
printf("\n\t B = %d : ",B);
for(i=0;i< =7;i++)
printf("%d ",n2[i]);
cin=0;
for(i=7;i>=0;i--)
{
sum[i]=exor(cin,exor(n1[i],n2[i])); // Sum Pi (+) Bi
cg[i]=and(n1[i],n2[i]); // Gi = Ai . Bi
cp[i]=or(n1[i],n2[i]); // Pi = Ai (+) Bi
cin=or(cg[i],and(cp[i],cin)); // Cin =Gi + PiCi
}
printf("\n\n\t\t SUM: ");
num=0;
for(i=0;i< =7;i++)
{
printf(" %d",sum[i]);
num=num + (sum[i]*pow(2,7-i));
}
printf("\n\n\t\t SUM: %d + %d= %d\n",A,B,num);
printf("\t\t The Carry Is : %d\n\n",cin);
}

void main()
{
int ch,a,b,c,d;
clrscr();
while(1)
{
M: printf("******** MENU FOR LOOK AHEAD CARRY ADDER ********");
printf("\n\t\t1.ADDITION OF TWO NUMBER");
printf("\n\t\t2.EXIT\n");
printf("*************************************************");
printf("\n\t\tEnter Your Option:");
scanf("%d",&ch);
switch(ch)
{
case 1:
add();
getch();
break;

case 2: exit(0);
break;

default:
clrscr();
printf("ERROR!!!!!!!!! INVALID ENTRY...\n");
printf("Back To Main Menu\n\n");
goto M;
}
}
}


/*------------------ OUTPUT --------------------

******** MENU FOR LOOK AHEAD CARRY ADDER ********
1.ADDITION OF TWO NUMBER
2.EXIT
*************************************************
Enter Your Option:1

ENTER VALUE OF A:2

ENTER VALUE OF B:3

Binary Form
A = 2 : 0 0 0 0 0 0 1 0
B = 3 : 0 0 0 0 0 0 1 1

SUM: 0 0 0 0 0 1 0 1

SUM: 2 + 3= 5
The Carry Is : 0

******** MENU FOR LOOK AHEAD CARRY ADDER ********
1.ADDITION OF TWO NUMBER
2.EXIT
*************************************************
Enter Your Option:2 */