C-Program to Conversion of Binary Code to Decimal,Octal,Hexadecimal

#include<stdio.h>
#include<stdlib.h>
main()
{
int b,d,z,r,t,y[50],i,j,dec,x[50];
printf("Enter the Binary Number\t");
scanf("%d",&b);
t=b;
z=1;
d=0;
if(b==0)
{
printf("Decimal Equivalant of %d is 0\n",b);
printf("Octal Equivalant of %d is 0\n",b);
printf("HexaDecimal Equivalant of %d is 0",b);
exit(0);
}
while(b>0)
{
r=b%10;
if(r>1)
{
printf("\n Invalid Entry");
exit(0);
}
d=d+(z*r);
z=z*2;
b=b/10;
}
dec=d;
j=0;
while(d>0)
{
r=d%8;
x[j]=r;
j++;
d=d/8;
}
d=dec;
j=0;
while(d>0)
{
r=d%16;
y[j]=r;
j++;
d=d/16;
}
printf("Decimal Equivalant of %d is \t%d\n",t,dec);
printf("Octal Equivalant of %d is \t",t);
for(i=j-1;i>=0;i--)
printf("%d",x[i]);
printf("\nHexaDecimal Equivalant of %d is\t",t);
for(i=j-1;i>=0;i--)
{  
switch(y[i])
{
case 10:
printf("A");
break;
case 11:
printf("B");
break;
case 12:
printf("C");
break;
case 13:
printf("D");
break;
case 14:
printf("E");
break;
case 15:
printf("F");
break;
default:
printf("%d",y[i]);
        break;
}
}
}

output