java 백준1009번문제1번째풀이

Posted 2021-05-07

import java.util.Scanner;
public class Main {
    public static void main(String args[]) {
        int a, b, T, r;
        Scanner sc = new Scanner(System.in);
        T = sc.nextInt();
        for (int i = 0; i<T; ++i) {
            a = (sc.nextInt())%10;
            b = (sc.nextInt());
            if (a == 0) {
                System.out.println("10");
                continue;
            }
            // 페르마 지수 계산
	    r = 1;
            while(b>0) {
                if(b%2 == 1) r *= a;
                a *= a;
		a %= 10;
		r %= 10;
                b /= 2;
            }
            System.out.println(r%10);
        }
    }
}