蓝桥杯 有理数类

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蓝桥杯 有理数类

蓝桥杯 有理数类

标题：有理数类

有理数就是可以表示为两个整数的比值的数字。一般情况下，我们用近似的小数表示。但有些时候，不允许出现误差，必须用两个整数来表示一个有理数。

这时，我们可以建立一个“有理数类”，下面的代码初步实现了这个目标。为了简明，它只提供了加法和乘法运算。

class Rational
{private long ra;private long rb;private long gcd(long a, long b){if(b==0) return a;return gcd(b,a%b);}public Rational(long a, long b){ra = a;rb = b;long k = gcd(ra,rb);if(k>1){ //需要约分ra /= k;rb /= k;}}// 加法public Rational add(Rational x){return ________________________________________;  //填空位置}// 乘法public Rational mul(Rational x){return new Rational(ra*x.ra, rb*x.rb);}public String toString(){if(rb==1) return "" + ra;return ra + "/" + rb;}
}

使用该类的示例：

Rational a = new Rational(1,3);
Rational b = new Rational(1,6);
Rational c = a.add(b);
System.out.println(a + "+" + b + "=" + c);

请分析代码逻辑，并推测划线处的代码，通过网页提交
注意：仅把缺少的代码作为答案，千万不要填写多余的代码、符号或说明文字！！

public class 有理数类 {public static void main(String[] args) {Rational a = new Rational(1,3);Rational b = new Rational(1,6);Rational c = a.add(b);System.out.println(a + "+" + b + "=" + c);}static class Rational {private long ra;private long rb;private long gcd(long a, long b) {if (b == 0) return a;return gcd(b, a % b);}public Rational(long a, long b) {ra = a;rb = b;long k = gcd(ra, rb);if (k > 1) { //需要约分ra /= k;rb /= k;}}// 加法public Rational add(Rational x) {return new Rational(this.ra * x.rb + x.ra * this.rb, this.rb * x.rb);  //填空位置}// 乘法public Rational mul(Rational x) {return new Rational(ra * x.ra, rb * x.rb);}public String toString() {if (rb == 1) return "" + ra;return ra + "/" + rb;}}}