Seriously Whats wrong with my code

[iamsethi]

I am trying to solve a Problem code: LASTDIG2 in SPOJ SPOJ.com - Problem LASTDIG2
but every time i am getting 'WA': Wrong Answer
I have tried every posible Test Cases.I've written the code mentioned below.Please help

#include <stdio.h>
int main() {
     int t;
    scanf("%d",&t);
    while(t--)
    {
     signed long long int b,c;
        scanf("%llu %llu",&b,&c);
        b=b%10;
            if((c==0)&& (b!=0))  printf("%d\n",1);
            else
            {
                    if((c%4)==0)
                    printf("%d\n",((int)pow(b,4))%10);
                    else
                    printf("%d\n",((int)pow(b,c%4))%10);
            }



    }
    return 0;
}

When i googled for the solution i found the below code and the below mentioned code is 'Acepted' by Spoj:

#include<stdio.h>
#include<string.h>
int main()
{
char str[1005];
unsigned long long int b,a,ans,len,t;
scanf("%llu",&t); 
while(t--){
scanf("%s",str);
scanf("%llu",&b);
 len=strlen(str);
a=str[len-1]-'0'; 
if(b==0&&a!=0) ans=1; 
else{
if(a==0){ ans=0; goto end;}
if(a==5) {ans=5; goto end;}
switch(b%4){
case 0: ans=a%2!=0? 1:6;
break;
case 1: ans=a;
break;
case 2: ans=a*a%10;
break;
default : ans=a*a*a%10;
break; 
}
}
end :
printf("%llu\n",ans);
}
return 0;
}

[GReaper]

You seem to miss something, and that probably that in what the problem wants you to do("a^b"), "a" will be far bigger than what a "long long" can support.

[iamsethi]

You seem to miss something, and that probably that in what the problem wants you to do("a^b"), "a" will be far bigger than what a "long long" can support.

The problem mentions that range of a should be 1<=a<=1000

[stahta01]

The problem mentions that range of a should be 1<=a<=1000

Wrong it means a can have 1 to 1000 digits in it.

Tim S.

[Aslaville]

The problem mentions that range of a should be 1<=a<=1000

Wrong it means a can have 1 to 1000 digits in it.

You could treat the digits as 8-bit characters and hold them in an array as the code you got from the interwebs does.