Question

用JAVA 计算两个非零正整数的最大公约数和最小公倍数，要求两个非零正整数从键盘输入

新手上路 请多注释！
先谢谢啦

Answer 1

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

public class Test {

public static void main(String[] args) {
/* Gets two numbers from keyboard */
Scanner scanner = new Scanner(System.in);
BigInteger firstNumber = getNumber("Enter the first number: ", scanner);
BigInteger secondNumber = getNumber("Enter the second number: ", scanner);

/* Calculates the greatest common divisor */
BigInteger gcd = firstNumber.gcd(secondNumber);
/* Calculates the least common multiple */
BigInteger lcm = firstNumber.multiply(secondNumber).divide(gcd);

/* Prints out the results */
System.out.println("Greatest Common Divison: " + gcd);
System.out.println("Least Common Multiple: " + lcm);

}

/**
* Gets a number from keyboard
*/
static BigInteger getNumber(String message, Scanner scanner) {
while (true) {
try {
System.out.println(message); // displays the message
String number = scanner.next(); // gets a token
BigInteger integer = new BigInteger(number); // Constructs an integer object
if (integer.compareTo(BigInteger.ZERO) < 0) {
throw new NumberFormatException(); // number less than 0 is not allowed
}
return integer;
} catch (NumberFormatException e) {
System.out.println("Invalid number!"); // if not a number, repeat
}
}
}
}