SPOJ LASTDIG

LASTDIG.cpp

    #include <bits/stdc++.h>
    using namespace std;
     
    int main(){
    	long long int t,a,b,rm,lst,ans;
    	int ar[] = {0,0,4,4,2,1,1,4,4,2};
    	cin >> t;
    	while(t--){
            cin >> a >> b;
            lst=a%10;
            if(lst == 1 || b == 0){
                ans = 1;
            } else if(lst == 0){
                ans = 0;
            } else{
                rm = ar[lst];
                rm = b % rm;
                if(rm == 1) ans = (int)pow(lst,1)%10;
                else if(rm == 2) ans = (int)pow(lst,2)%10;
                else if(rm == 3) ans = (int)pow(lst,3)%10;
                else ans = (int)pow(lst,4)%10;
            }
            cout << ans << endl;
    	}
    	return 0;
     
    }