why WA............?plz help.

[ongkon]

i got wrong answer in this problem. But did not find the problem in the code. please help me...........
Here is my code:

#include<stdio.h>
#include<string.h>
#include<ctype.h>
#include<math.h>
#define MAX 13

void main()
{
char arr1[5],arr2[5],ch;
long num1[MAX],num2[MAX],n,a,b,c,d,i,j,k,l,p,q;

/*freopen("g:\in1.txt","rt",stdin);*/

scanf("%ld",&n);
for(k=0;k<n;k++)
{
scanf("%s %c %s",arr1,&ch,arr2);
a=strlen(arr1);
b=strlen(arr2);
for(i=0;i<a;i++)
arr1=toupper(arr1);
for(i=0;i<b;i++)
arr2=toupper(arr2);

p=0;
c=a-1;
for(j=0;j<a;j++)
{
if(arr1[j]<=57)
p+=(long(arr1[j])-48)*(long(pow(16,c)));
else
p+=(long(arr1[j])-55)*(long(pow(16,c)));
c--;
}
q=0;
c=b-1;
for(j=0;j<b;j++)
{
if(arr2[j]<=57)
q+=(long(arr2[j])-48)*(long(pow(16,c)));
else
q+=(long(arr2[j])-55)*(long(pow(16,c)));
c--;
}
for(i=0;i<=MAX;i++)
{
num1=0;
num2=0;
}
c=MAX;
d=p;
while(d!=0)
{
num1[c]=d%2;
d=long(d/2);
c--;
}
c=MAX;
d=q;
while(d!=0)
{
num2[c]=d%2;
d=long(d/2);
c--;
}
for(i=1;i<=MAX;i++)
printf("%ld",num1);
printf(" %c ",ch);

for(i=1;i<=MAX;i++)
printf("%ld",num2);
printf(" = ");
if(ch=='+')
printf("%ld",p+q);
else
printf("%ld",p-q);
printf("\n");
}
}

[/code][/c]