HDU-1715大菲波数Java

%2を通過する配列を作成 フィボナッチ数を計算します
コードは次のとおりです.

import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Locale;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        BigInteger[] a = new BigInteger[2];
        int num, ca;
        ca = in.nextInt();
        while (ca-- > 0) {
            a[0] = a[1] = BigInteger.ONE;
            num = in.nextInt();
            for (int i = 3; i <= num; ++i) {
                a[i % 2] = a[i % 2].add(a[(i - 1) % 2]);
            }
            System.out.println(a[num%2]);
        }
    }
}