本体建议参考Java的kpi 文档中的BigInteger 中的gcd方法
求取最大公倍数
import java.math.BigInteger;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
String[] arr1 = scanner.nextLine().split("/");
String[] arr2 = scanner.nextLine().split("/");
BigInteger a = new BigInteger(Integer.toString(Integer.parseInt(arr1[0])*Integer.parseInt(arr2[0])));
BigInteger b = new BigInteger(Integer.toString(Integer.parseInt(arr1[1])*Integer.parseInt(arr2[1])));
int gcd = a.gcd(b).intValue();
System.out.println((b.intValue()/gcd) + " " + (a.intValue()/gcd));
}
}