HDU 1051 - Rightmost Digit

#include <iostream>
#include <cmath>
using namespace std;
int t,m,p,q;
long long n;
int c[15],ans;
int main()
{
scanf("%d",&t);
while(t--)
{
scanf("%lld",&n);
m=n%10;
int cnt=0,i;
c[++cnt]=m;
p=(m*m)%10;
while(p!=m)
{
c[++cnt]=p;
p=(p*m)%10;
}
ans=(n-1)%cnt+1;
printf("%d\n",c[ans]);
}
}
/*
3 9 7 1 3
4 6 4 6
*/