我使用BigInteger创建了Rational类，但没有显示任何内容 import java.math.*； 导入java.util.Scanner； 公共班机{ 公共静态void main（字符串[]args）{ 扫描仪sc=新的扫描仪（System.in）； int T=sc.nextInt（）； for（int t=0；t0）？新的BigInteger（“1”）：新的BigInteger（“-1”）） .乘（分子除（gcd））； this.denominor=denominor.abs（）.除法（gcd）； } //求两个大整数的GCD 私有静态BigInteger gcd（BigInteger n，BigInteger d）{ BigInteger n1=n.abs（）； 大整数n2=d.abs（）； BigInteger gcd=BigInteger.1； for（biginger k=biginger.ONE；k.compareTo（n1）

biginger

是不可变的。您不能执行

k.add（biginger.ONE）

并期望

k

更改。您必须执行

k=k.add（biginger.ONE）

---

在构造过程中调用的

gcd

方法中可以实现这一点，因此第一次创建

Rational

gcd

时会进入一个无限循环。

biginger

是不可变的。你不能做

k.add（biginger.ONE）

而期望

k

改变。你必须做

k=k.add（BigInteger.ONE）

---

您可以在构建过程中调用的

gcd

方法中执行此操作，因此第一次创建

Rational

gcd

将进入无限循环。

@girlcrush请单击此答案旁边的复选标记图标将此问题标记为已解决。谢谢。@girlcrush请将此问题标记为cli已解决点击此答案旁边的复选标记图标。谢谢。谢谢。哦，现在程序工作，但时间限制超过了…；（谢谢。哦，现在程序工作，但时间限制超过了…）(

import java.math.*;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int T = sc.nextInt();

        for (int t = 0; t < T; t++) {
            Rational r1 = new Rational(new BigInteger(sc.next()), new BigInteger(sc.next()));
            Rational r2 = new Rational(new BigInteger(sc.next()), new BigInteger(sc.next()));

            System.out.println(r1 + " + " + r2 + " = " + r1.add(r2));
            System.out.println(r1 + " - " + r2 + " = " + r1.subtract(r2));
            System.out.println(r1 + " * " + r2 + " = " + r1.multiply(r2));
            System.out.println(r1 + " / " + r2 + " = " + r1.divide(r2));
        }
    }
}

class Rational extends Number implements Comparable<Rational> {
    private static final long serialVersionUID = 1L;
    private BigInteger numerator = BigInteger.ZERO;
    private BigInteger denominator = BigInteger.ONE;

    public Rational() {
        this(BigInteger.ZERO, BigInteger.ONE);
    }
    // set numerator and denominator
    public Rational(BigInteger numerator, BigInteger denominator) {
        BigInteger gcd = gcd(numerator, denominator);
        this.numerator = ((denominator.compareTo(BigInteger.ZERO) > 0) ? new BigInteger("1") : new BigInteger("-1"))
            .multiply(numerator.divide(gcd));
        this.denominator = denominator.abs().divide(gcd);
    }
    // Find GCD of two BigIntegers
    private static BigInteger gcd(BigInteger n, BigInteger d) {
        BigInteger n1 = n.abs();
        BigInteger n2 = d.abs();
        BigInteger gcd = BigInteger.ONE;

        for (BigInteger k = BigInteger.ONE; k.compareTo(n1) <= 0 && k.compareTo(n2) <= 0; k.add(BigInteger.ONE)) {
            if (n1.mod(k).equals(BigInteger.ZERO) && n2.mod(k).equals(BigInteger.ZERO))
                gcd = k;
        }
        return gcd;
    }

    public BigInteger getNumerator() {
        return numerator;
    }

    public BigInteger getDenominator() {
        return denominator;
    }

    public Rational add(Rational secondRational) {
        BigInteger n = (numerator.multiply(secondRational.getDenominator()))
            .add(denominator.multiply(secondRational.getNumerator()));
        BigInteger d = denominator.multiply(secondRational.getDenominator());
        return new Rational(n, d);
    }

    public Rational subtract(Rational secondRational) {
        BigInteger n = (numerator.multiply(secondRational.getDenominator()))
            .subtract(denominator.multiply(secondRational.getNumerator()));
        BigInteger d = denominator.multiply(secondRational.getDenominator());
        return new Rational(n, d);
    }

    public Rational multiply(Rational secondRational) {
        BigInteger n = numerator.multiply(secondRational.getNumerator());
        BigInteger d = denominator.multiply(secondRational.getDenominator());
        return new Rational(n, d);
    }

    public Rational divide(Rational secondRational) {
        BigInteger n = numerator.multiply(secondRational.getDenominator());
        BigInteger d = denominator.multiply(secondRational.numerator);
        return new Rational(n, d);
    }

    @Override
    public String toString() {
        if (denominator.compareTo(BigInteger.ONE) == 0)
            return numerator + "";
        else
            return numerator + "/" + denominator;
    }

    @Override
    public boolean equals(Object other) {
        if ((this.subtract((Rational) (other))).getNumerator().equals(BigInteger.ZERO))
            return true;
        else
            return false;
    }

    @Override
    public int intValue() {
        return (int) doubleValue();
    }

    @Override
    public float floatValue() {
        return (float) doubleValue();
    }

    @Override
    public double doubleValue() {
        double x = this.getNumerator().doubleValue();
        double y = this.getDenominator().doubleValue();
        return x / y;
    }

    @Override
    public long longValue() {
        return (long) doubleValue();
    }

    @Override
    public int compareTo(Rational o) {
        if (this.subtract(o).getNumerator().compareTo(BigInteger.ZERO) > 0)
            return 1;
        else if (this.subtract(o).getNumerator().compareTo(BigInteger.ZERO) < 0)
            return -1;
        else
            return 0;
    }
}